Science.gov

Sample records for probing hidden sector

  1. Probing hidden sectors with Stückelberg U(1) gauge fields.

    PubMed

    Feng, Wan-Zhe; Shiu, Gary; Soler, Pablo; Ye, Fang

    2014-08-01

    We propose a framework in which visible matter interacts with matter from a hidden sector through mass mixings of Stückelberg U(1) gauge fields. In contrast to other Z(') mediation scenarios, our setup has the added appealing features that (i) the choice of Z(')'s can be significantly broadened without necessarily introducing unwanted exotic matter and (ii) there can be sizable tree-level interactions between the visible and hidden sectors. String theory embeddings of this scenario and their phenomenological features are briefly discussed. PMID:25148316

  2. Probing Dark Forces and Light Hidden Sectors at Low-Energy e+e- Colliders

    SciTech Connect

    Essig, Rouven; Schuster, Philip; Toro, Natalia; /Stanford U., ITP

    2009-06-19

    A dark sector - a new non-Abelian gauge group Higgsed or confined near the GeV scale - can be spectacularly probed in low-energy e{sup +}e{sup -} collisions. A low-mass dark sector can explain the annual modulation signal reported by DAMA/LIBRA and the PAMELA, ATIC, and INTEGRAL observations by generating small mass splittings and new interactions for weak-scale dark matter. Some of these observations may be the first signs of a low-mass dark sector that collider searches can definitively confirm. Production and decay of {Omicron}(GeV)-mass dark states is mediated by a Higgsed Abelian gauge boson that mixes kinetically with hypercharge. Existing data from BaBar, BELLE, CLEO-c, and KLOE may contain thousands of striking dark-sector events with a high multiplicity of leptons that reconstruct mass resonances and possibly displaced vertices. We discuss the production and decay phenomenology of Higgsed and confined dark sectors and propose e{sup +}e{sup -} collider search strategies. We also use the DAMA/LIBRA signal to estimate the production cross-sections and decay lifetimes for dark-sector states.

  3. Dissipative hidden sector dark matter

    NASA Astrophysics Data System (ADS)

    Foot, R.; Vagnozzi, S.

    2015-01-01

    A simple way of explaining dark matter without modifying known Standard Model physics is to require the existence of a hidden (dark) sector, which interacts with the visible one predominantly via gravity. We consider a hidden sector containing two stable particles charged under an unbroken U (1 )' gauge symmetry, hence featuring dissipative interactions. The massless gauge field associated with this symmetry, the dark photon, can interact via kinetic mixing with the ordinary photon. In fact, such an interaction of strength ε ˜10-9 appears to be necessary in order to explain galactic structure. We calculate the effect of this new physics on big bang nucleosynthesis and its contribution to the relativistic energy density at hydrogen recombination. We then examine the process of dark recombination, during which neutral dark states are formed, which is important for large-scale structure formation. Galactic structure is considered next, focusing on spiral and irregular galaxies. For these galaxies we modeled the dark matter halo (at the current epoch) as a dissipative plasma of dark matter particles, where the energy lost due to dissipation is compensated by the energy produced from ordinary supernovae (the core-collapse energy is transferred to the hidden sector via kinetic mixing induced processes in the supernova core). We find that such a dynamical halo model can reproduce several observed features of disk galaxies, including the cored density profile and the Tully-Fisher relation. We also discuss how elliptical and dwarf spheroidal galaxies could fit into this picture. Finally, these analyses are combined to set bounds on the parameter space of our model, which can serve as a guideline for future experimental searches.

  4. Lepton mixing from the hidden sector

    NASA Astrophysics Data System (ADS)

    Ludl, P. O.; Smirnov, A. Yu.

    2015-10-01

    Experimental results indicate a possible relation between the lepton and quark mixing matrices of the form UPMNS≈VCKM†UX , where UX is a matrix with special structure related to the mechanism of neutrino mass generation. We propose a framework which can realize such a relation. The main ingredients of the framework are the double seesaw mechanism, SO(10) grand unification and a hidden sector of theory. The latter is composed of singlets (fermions and bosons) of the grand unified theory (GUT) symmetry with masses between the GUT and Planck scale. The interactions in this sector obey certain symmetries Ghidden. We explore the conditions under which symmetries Ghidden can produce flavor structures in the visible sector. Here the key elements are the basis-fixing symmetry and mediators which communicate information about properties of the hidden sector to the visible one. The interplay of SO(10) symmetry, basis-fixing symmetry identified as Z2×Z2 and Ghidden can lead to the required form of UX. A different kind of new physics is responsible for generation of the CKM mixing. We present the simplest realizations of the framework which differ by nature of the mediators and by symmetries of the hidden sector.

  5. More visible effects of the hidden sector

    SciTech Connect

    Murayama, Hitoshi; Murayama, Hitoshi; Nomura, Yasunori; Poland, David

    2007-09-06

    There is a growing appreciation that hidden sector dynamics may affect the supersymmetry breaking parameters in the visible sector (supersymmetric standard model), especially when the dynamics is strong and superconformal. We point out that there are effects that have not been previously discussed in the literature. For example, the gaugino masses are suppressed relative to the gravitino mass. We discuss their implications in the context of various mediation mechanisms. The issues discussed include anomaly mediation with singlets, the mu (B mu) problem in gauge and gaugino mediation, and distinct mass spectra for the superparticles that have not been previously considered.

  6. Abelian Hidden Sectors at a GeV

    SciTech Connect

    Morrissey, David E.; Poland, David; Zurek, Kathryn; /Fermilab /Michigan U.

    2009-04-16

    We discuss mechanisms for naturally generating GeV-scale hidden sectors in the context of weak-scale supersymmetry. Such low mass scales can arise when hidden sectors are more weakly coupled to supersymmetry breaking than the visible sector, as happens when supersymmetry breaking is communicated to the visible sector by gauge interactions under which the hidden sector is uncharged, or if the hidden sector is sequestered from gravity-mediated supersymmetry breaking. We study these mechanisms in detail in the context of gauge and gaugino mediation, and present specific models of Abelian GeV-scale hidden sectors. In particular, we discuss kinetic mixing of a U(1){sub x} gauge force with hypercharge, singlets or bi-fundamentals which couple to both sectors, and additional loop effects. Finally, we investigate the possible relevance of such sectors for dark matter phenomenology, as well as for low- and high-energy collider searches.

  7. Supersymmetric leptogenesis with a light hidden sector

    SciTech Connect

    De Simone, Andrea; Garny, Mathias; Ibarra, Alejandro; Weniger, Christoph E-mail: mathias.garny@ph.tum.de E-mail: christoph.weniger@desy.de

    2010-07-01

    Supersymmetric scenarios incorporating thermal leptogenesis as the origin of the observed matter-antimatter asymmetry generically predict abundances of the primordial elements which are in conflict with observations. In this paper we propose a simple way to circumvent this tension and accommodate naturally thermal leptogenesis and primordial nucleosynthesis. We postulate the existence of a light hidden sector, coupled very weakly to the Minimal Supersymmetric Standard Model, which opens up new decay channels for the next-to-lightest supersymmetric particle, thus diluting its abundance during nucleosynthesis. We present a general model-independent analysis of this mechanism as well as two concrete realizations, and describe the relevant cosmological and astrophysical bounds and implications for this dark matter scenario. Possible experimental signatures at colliders and in cosmic-ray observations are also discussed.

  8. Exploring portals to a hidden sector through fixed targets

    SciTech Connect

    Batell, Brian; Pospelov, Maxim; Ritz, Adam

    2009-11-01

    We discuss the sensitivity of neutrino experiments at the luminosity frontier to generic hidden sectors containing new (sub)-GeV neutral states. The weak interaction of these states with the standard model can be efficiently probed through all of the allowed renormalizable 'portals' (in the Higgs, vector, and neutrino sectors) at fixed target proton beam facilities, with complementary sensitivity to colliders. We concentrate on the kinetic-mixing vector portal, and show that certain regions of the parameter space for a new U(1){sub S} gauge sector with long-lived sub-GeV mass states decaying to standard model leptons are already severely constrained by the data sets at LSND, MiniBooNE, and NuMI/MINOS. Furthermore, scenarios in which portals allow access to stable neutral particles, such as MeV-scale dark matter, generally predict that the neutrino beam is accompanied by a 'dark matter beam', observable through neutral-current-like interactions in the detector. As a consequence, we show that the LSND electron recoil event sample currently provides the most stringent direct constraint on MeV-scale dark matter models.

  9. Gauge mediation scenario with hidden sector renormalization in MSSM

    SciTech Connect

    Arai, Masato; Okada, Nobuchika

    2010-02-01

    We study the hidden sector effects on the mass renormalization of a simplest gauge-mediated supersymmetry breaking scenario. We point out that possible hidden sector contributions render the soft scalar masses smaller, resulting in drastically different sparticle mass spectrum at low energy. In particular, in the 5+5 minimal gauge-mediated supersymmetry breaking with high messenger scale (that is favored by the gravitino cold dark matter scenario), we show that a stau can be the next lightest superparticle for moderate values of hidden sector self-coupling. This provides a very simple theoretical model of long-lived charged next lightest superparticles, which imply distinctive signals in ongoing and upcoming collider experiments.

  10. Diurnal modulation signal from dissipative hidden sector dark matter

    NASA Astrophysics Data System (ADS)

    Foot, R.; Vagnozzi, S.

    2015-09-01

    We consider a simple generic dissipative dark matter model: a hidden sector featuring two dark matter particles charged under an unbroken U(1) ‧ interaction. Previous work has shown that such a model has the potential to explain dark matter phenomena on both large and small scales. In this framework, the dark matter halo in spiral galaxies features nontrivial dynamics, with the halo energy loss due to dissipative interactions balanced by a heat source. Ordinary supernovae can potentially supply this heat provided kinetic mixing interaction exists with strength ɛ ∼10-9. This type of kinetically mixed dark matter can be probed in direct detection experiments. Importantly, this self-interacting dark matter can be captured within the Earth and shield a dark matter detector from the halo wind, giving rise to a diurnal modulation effect. We estimate the size of this effect for detectors located in the Southern hemisphere, and find that the modulation is large (≳ 10%) for a wide range of parameters.

  11. Hidden sector DM models and Higgs physics

    SciTech Connect

    Ko, P.

    2014-06-24

    We present an extension of the standard model to dark sector with an unbroken local dark U(1){sub X} symmetry. Including various singlet portal interactions provided by the standard model Higgs, right-handed neutrinos and kinetic mixing, we show that the model can address most of phenomenological issues (inflation, neutrino mass and mixing, baryon number asymmetry, dark matter, direct/indirect dark matter searches, some scale scale puzzles of the standard collisionless cold dark matter, vacuum stability of the standard model Higgs potential, dark radiation) and be regarded as an alternative to the standard model. The Higgs signal strength is equal to one as in the standard model for unbroken U(1){sub X} case with a scalar dark matter, but it could be less than one independent of decay channels if the dark matter is a dark sector fermion or if U(1){sub X} is spontaneously broken, because of a mixing with a new neutral scalar boson in the models.

  12. Cosmic strings in hidden sectors: 2. Cosmological and astrophysical signatures

    SciTech Connect

    Long, Andrew J.; Vachaspati, Tanmay

    2014-12-18

    Cosmic strings can arise in hidden sector models with a spontaneously broken Abelian symmetry group. We have studied the couplings of the Standard Model fields to these so-called dark strings in the companion paper. Here we survey the cosmological and astrophysical observables that could be associated with the presence of dark strings in our universe with an emphasis on low-scale models, perhaps TeV. Specifically, we consider constraints from nucleosynthesis and CMB spectral distortions, and we calculate the predicted fluxes of diffuse gamma ray cascade photons and cosmic rays. For strings as light as TeV, we find that the predicted level of these signatures is well below the sensitivity of the current experiments, and therefore low scale cosmic strings in hidden sectors remain unconstrained. Heavier strings with a mass scale in the range 10{sup 13} GeV to 10{sup 15} GeV are at tension with nucleosynthesis constraints.

  13. Cosmic strings in hidden sectors: 2. Cosmological and astrophysical signatures

    SciTech Connect

    Long, Andrew J.; Vachaspati, Tanmay E-mail: tvachasp@asu.edu

    2014-12-01

    Cosmic strings can arise in hidden sector models with a spontaneously broken Abelian symmetry group. We have studied the couplings of the Standard Model fields to these so-called dark strings in the companion paper. Here we survey the cosmological and astrophysical observables that could be associated with the presence of dark strings in our universe with an emphasis on low-scale models, perhaps TeV . Specifically, we consider constraints from nucleosynthesis and CMB spectral distortions, and we calculate the predicted fluxes of diffuse gamma ray cascade photons and cosmic rays. For strings as light as TeV, we find that the predicted level of these signatures is well below the sensitivity of the current experiments, and therefore low scale cosmic strings in hidden sectors remain unconstrained. Heavier strings with a mass scale in the range 10{sup 13} GeV to 10{sup 15} GeV are at tension with nucleosynthesis constraints.

  14. Scale invariant extension of the standard model with a strongly interacting hidden sector.

    PubMed

    Hur, Taeil; Ko, P

    2011-04-01

    We present a scale invariant extension of the standard model with a new QCD-like strong interaction in the hidden sector. A scale Λ(H) is dynamically generated in the hidden sector by dimensional transmutation, and chiral symmetry breaking occurs in the hidden sector. This scale is transmitted to the SM sector by a real singlet scalar messenger S and can trigger electroweak symmetry breaking. Thus all the mass scales in this model arise from the hidden sector scale Λ(H), which has quantum mechanical origin. Furthermore, the lightest hadrons in the hidden sector are stable by the flavor conservation of the hidden sector strong interaction, and could be the cold dark matter (CDM). We study collider phenomenology, relic density, and direct detection rates of the CDM of this model. PMID:21561182

  15. Renormalization effects on the MSSM from a calculable model of a strongly coupled hidden sector

    SciTech Connect

    Arai, Masato; Okada, Nobuchika

    2011-10-01

    We investigate possible renormalization effects on the low-energy mass spectrum of the minimal supersymmetric standard model (MSSM), using a calculable model of strongly coupled hidden sector. We model the hidden sector by N=2 supersymmetric quantum chromodynamics with gauge group SU(2)xU(1) and N{sub f}=2 matter hypermultiplets, perturbed by a Fayet-Iliopoulos term which breaks the supersymmetry down to N=0 on a metastable vacuum. In the hidden sector the Kaehler potential is renormalized. Upon identifying a hidden sector modulus with the renormalization scale, and extrapolating to the strongly coupled regime using the Seiberg-Witten solution, the contribution from the hidden sector to the MSSM renormalization group flows is computed. For concreteness, we consider a model in which the renormalization effects are communicated to the MSSM sector via gauge mediation. In contrast to the perturbative toy examples of hidden sector renormalization studied in the literature, we find that our strongly coupled model exhibits rather intricate effects on the MSSM soft scalar mass spectrum, depending on how the hidden sector fields are coupled to the messenger fields. This model provides a concrete example in which the low-energy spectrum of MSSM particles that are expected to be accessible in collider experiments is obtained using strongly coupled hidden sector dynamics.

  16. A cavity experiment to search for hidden sector photons

    NASA Astrophysics Data System (ADS)

    Jaeckel, Joerg; Ringwald, Andreas

    2008-01-01

    We propose a cavity experiment to search for low mass extra U(1) gauge bosons with gauge-kinetic mixing with the ordinary photon, so-called paraphotons. The setup consists of two microwave cavities shielded from each other. In one cavity, paraphotons are produced via photon-paraphoton oscillations. The second, resonant, cavity is then driven by the paraphotons that permeate the shielding and reconvert into photons. This setup resembles the classic "light shining through a wall" setup. However, the high quality factors achievable for microwave cavities and the good sensitivity of microwave detectors allow for a projected sensitivity for photon-paraphoton mixing of the order of χ ∼10-12-10-8, for paraphotons with masses in the μeV to meV range-exceeding the current laboratory and astrophysics-based limits by several orders of magnitude. Therefore, this experiment bears significant discovery potential for hidden sector physics.

  17. Multilepton signatures of a hidden sector in rare B decays

    SciTech Connect

    Batell, Brian; Pospelov, Maxim; Ritz, Adam

    2011-03-01

    We explore the sensitivity of flavor-changing b{yields}s transitions to a (sub-) GeV hidden sector with generic couplings to the standard model through the Higgs, vector, and axion portals. The underlying two-body decays of B mesons, B{yields}X{sub s}S, and B{sup 0}{yields}SS, where S denotes a generic new GeV-scale particle, may significantly enhance the yield of monochromatic lepton pairs in the final state via prompt S{yields}ll decays. Existing measurements of the charged lepton spectrum in neutral-current semileptonic B decays provide bounds on the parameters of the light sector that are significantly more stringent than the requirements of naturalness. New search modes, such as B{yields}X{sub s}+n(ll) and B{sup 0}{yields}n(ll) with n{>=}2, can provide additional sensitivity to scenarios in which both the Higgs and vector portals are active, and are accessible to (super-) B factories and hadron colliders.

  18. Hidden from view: coupled dark sector physics and small scales

    NASA Astrophysics Data System (ADS)

    Elahi, Pascal J.; Lewis, Geraint F.; Power, Chris; Carlesi, Edoardo; Knebe, Alexander

    2015-09-01

    We study cluster mass dark matter (DM) haloes, their progenitors and surroundings in a coupled dark matter-dark energy (DE) model and compare it to quintessence and Λ cold dark matter (ΛCDM) models with adiabatic zoom simulations. When comparing cosmologies with different expansions histories, growth functions and power spectra, care must be taken to identify unambiguous signatures of alternative cosmologies. Shared cosmological parameters, such as σ8, need not be the same for optimal fits to observational data. We choose to set our parameters to ΛCDM z = 0 values. We find that in coupled models, where DM decays into DE, haloes appear remarkably similar to ΛCDM haloes despite DM experiencing an additional frictional force. Density profiles are not systematically different and the subhalo populations have similar mass, spin, and spatial distributions, although (sub)haloes are less concentrated on average in coupled cosmologies. However, given the scatter in related observables (V_max,R_{V_max}), this difference is unlikely to distinguish between coupled and uncoupled DM. Observations of satellites of Milky Way and M31 indicate a significant subpopulation reside in a plane. Coupled models do produce planar arrangements of satellites of higher statistical significance than ΛCDM models; however, in all models these planes are dynamically unstable. In general, the non-linear dynamics within and near large haloes masks the effects of a coupled dark sector. The sole environmental signature we find is that small haloes residing in the outskirts are more deficient in baryons than their ΛCDM counterparts. The lack of a pronounced signal for a coupled dark sector strongly suggests that such a phenomena would be effectively hidden from view.

  19. Hidden sector monopole, vector dark matter and dark radiation with Higgs portal

    SciTech Connect

    Baek, Seungwon; Ko, P.; Park, Wan-Il E-mail: pko@kias.re.kr

    2014-10-01

    We show that the 't Hooft-Polyakov monopole model in the hidden sector with Higgs portal interaction makes a viable dark matter model, where monopole and massive vector dark matter (VDM) are stable due to topological conservation and the unbroken subgroup U(1 {sub X}. We show that, even though observed CMB data requires the dark gauge coupling to be quite small, a right amount of VDM thermal relic can be obtained via s-channel resonant annihilation for the mass of VDM close to or smaller than the half of SM higgs mass, thanks to Higgs portal interaction. Monopole relic density turns out to be several orders of magnitude smaller than the observed dark matter relic density. Direct detection experiments, particularly, the projected XENON1T experiment, may probe the parameter space where the dark Higgs is lighter than ∼< 50 GeV. In addition, the dark photon associated with the unbroken U(1 {sub X} contributes to the radiation energy density at present, giving Δ N{sub eff}{sup ν} ∼ 0.1 as the extra relativistic neutrino species.

  20. Model-independent indirect detection constraints on hidden sector dark matter

    NASA Astrophysics Data System (ADS)

    Elor, Gilly; Rodd, Nicholas L.; Slatyer, Tracy R.; Xue, Wei

    2016-06-01

    If dark matter inhabits an expanded ``hidden sector'', annihilations may proceed through sequential decays or multi-body final states. We map out the potential signals and current constraints on such a framework in indirect searches, using a model-independent setup based on multi-step hierarchical cascade decays. While remaining agnostic to the details of the hidden sector model, our framework captures the generic broadening of the spectrum of secondary particles (photons, neutrinos, e+e‑ and bar p p) relative to the case of direct annihilation to Standard Model particles. We explore how indirect constraints on dark matter annihilation limit the parameter space for such cascade/multi-particle decays. We investigate limits from the cosmic microwave background by Planck, the Fermi measurement of photons from the dwarf galaxies, and positron data from AMS-02. The presence of a hidden sector can change the constraints on the dark matter by up to an order of magnitude in either direction (although the effect can be much smaller). We find that generally the bound from the Fermi dwarfs is most constraining for annihilations to photon-rich final states, while AMS-02 is most constraining for electron and muon final states; however in certain instances the CMB bounds overtake both, due to their approximate independence on the details of the hidden sector cascade. We provide the full set of cascade spectra considered here as publicly available code with examples at http://web.mit.edu/lns/research/CascadeSpectra.html.

  1. Hidden sector dark matters and elusive Higgs boson(s) at the LHC

    SciTech Connect

    Ko, P.

    2012-07-27

    We consider two types of hidden sector dark matters (DM's), with and without QCD-like new strong interaction with confinement properties, and their interplays with the Standard Model (SM) Higgs boson. Assuming the hidden sector has only fermions (and gauge bosons in case of strongly interacting hidden sector), we have to introduce a real singlet scalar boson S as a messenger between the SM and the hidden sector dark matters. This singlet scalar will mix with the SM Higgs boson h, and we expect there are two Higgs-like scalar bosons H{sub 1} and H{sub 2}. Imposing all the relevant constraints from collider search bounds on Higgs boson, DM scattering cross section on proton and thermal relic density, we find that one of the two Higgs-like scalar bosons can easily escape the detections at the LHC. Recent results on the Higgs-like new boson with mass around with 125 GeV from the LHC will constrain this class of models, which is left for future study.

  2. Probing the non-minimal Higgs sector at the SSC

    SciTech Connect

    Gunion, J.F.; Haber, H.E.; Komamiya, S.; Yamamoto, H.; Barbaro-Galtieri, A.

    1987-11-01

    Non-minimal Higgs sectors occur in the Standard Model with more than one Higgs doublet, as well as in theories that go beyond the Standard Model. In this report, we discuss how Higgs search strategies must be altered, with respect to the Standard Model approaches, in order to probe the non-minimal Higgs sectors at the SSC.

  3. Possible explanation of indirect gamma ray signatures from hidden sector fermionic dark matter

    NASA Astrophysics Data System (ADS)

    Dutta Banik, Amit; Majumdar, Debasish; Biswas, Anirban

    2016-06-01

    We propose the existence of a hidden or dark sector besides the standard model (SM) of particle physics, whose members (both fermionic and bosonic) obey a local SU(2)_H gauge symmetry, while behaving like a singlet under the SM gauge group. However, the fermiomic fields of the dark sector also possess another global U(1)_H symmetry, which remains unbroken. The local SU(2)_H invariance of the dark sector is broken spontaneously when a scalar field in this sector acquires a vacuum expectation value (VEV), thereby generating masses to the dark gauge bosons and dark fermions charged under the SU(2)_H. The lightest fermion in this dark SU(2)_H sector can be a potential dark matter candidate. We first examine the viability of the model and constrain the model parameter space by theoretical constraints such as vacuum stability and by the experimental constraints such as Planck limit on relic density, LHC data, limits on spin-independent scattering cross section from dark matter direct search experiments etc. We then investigate the gamma rays from the pair annihilation of the proposed dark matter candidate at the Galactic Centre region. We also extend our calculations of gamma rays flux for the case of dwarf galaxies and compare the signatures of gamma rays obtained from these astrophysical sites.

  4. 3.55 keV line from exciting dark matter without a hidden sector

    SciTech Connect

    Berlin, Asher; DiFranzo, Anthony; Hooper, Dan

    2015-04-24

    In this study, models in which dark matter particles can scatter into a slightly heavier state which promptly decays to the lighter state and a photon (known as eXciting Dark Matter, or XDM) have been shown to be capable of generating the 3.55 keV line observed from galaxy clusters, while suppressing the flux of such a line from smaller halos, including dwarf galaxies. In most of the XDM models discussed in the literature, this up-scattering is mediated by a new light particle, and dark matter annihilations proceed into pairs of this same light state. In these models, the dark matter and the mediator effectively reside within a hidden sector, without sizable couplings to the Standard Model. In this paper, we explore a model of XDM that does not include a hidden sector. Instead, the dark matter both up-scatters and annihilates through the near resonant exchange of an O(102) GeV pseudoscalar with large Yukawa couplings to the dark matter and smaller, but non-neglibile, couplings to Standard Model fermions. The dark matter and the mediator are each mixtures of Standard Model singlets and SU(2)W doublets. We identify parameter space in which this model can simultaneously generate the 3.55 keV line and the gamma-ray excess observed from the Galactic center, without conflicting with constraints from colliders, direct detection experiments, or observations of dwarf galaxies.

  5. 3.55 keV line from exciting dark matter without a hidden sector

    DOE PAGESBeta

    Berlin, Asher; DiFranzo, Anthony; Hooper, Dan

    2015-04-24

    In this study, models in which dark matter particles can scatter into a slightly heavier state which promptly decays to the lighter state and a photon (known as eXciting Dark Matter, or XDM) have been shown to be capable of generating the 3.55 keV line observed from galaxy clusters, while suppressing the flux of such a line from smaller halos, including dwarf galaxies. In most of the XDM models discussed in the literature, this up-scattering is mediated by a new light particle, and dark matter annihilations proceed into pairs of this same light state. In these models, the dark matter andmore » the mediator effectively reside within a hidden sector, without sizable couplings to the Standard Model. In this paper, we explore a model of XDM that does not include a hidden sector. Instead, the dark matter both up-scatters and annihilates through the near resonant exchange of an O(102) GeV pseudoscalar with large Yukawa couplings to the dark matter and smaller, but non-neglibile, couplings to Standard Model fermions. The dark matter and the mediator are each mixtures of Standard Model singlets and SU(2)W doublets. We identify parameter space in which this model can simultaneously generate the 3.55 keV line and the gamma-ray excess observed from the Galactic center, without conflicting with constraints from colliders, direct detection experiments, or observations of dwarf galaxies.« less

  6. Fermion zero modes in the vortex background of a Chern-Simons-Higgs theory with a hidden sector

    NASA Astrophysics Data System (ADS)

    Lozano, Gustavo; Mohammadi, Azadeh; Schaposnik, Fidel A.

    2015-11-01

    In this paper we study a 2 + 1 dimensional system in which fermions are coupled to the self-dual topological vortex in U(1) × U(1) Chern-Simons theory, where both U(1) gauge symmetries are spontaneously broken. We consider two Abelian Higgs scalars with visible and hidden sectors coupled to a fermionic field through three interaction La-grangians, where one of them violates the fermion number. Using a fine tuning procedure, we could obtain the number of the fermionic zero modes which is equal to the absolute value of the sum of the vortex numbers in the visible and hidden sectors.

  7. Venus Express en route to probe the planet's hidden mysteries

    NASA Astrophysics Data System (ADS)

    2005-11-01

    Venus Express will eventually manoeuvre itself into orbit around Venus in order to perform a detailed study of the structure, chemistry and dynamics of the planet's atmosphere, which is characterised by extremely high temperatures, very high atmospheric pressure, a huge greenhouse effect and as-yet inexplicable "super-rotation" which means that it speeds around the planet in just four days. The European spacecraft will also be the first orbiter to probe the planet's surface while exploiting the "visibility windows" recently discovered in the infrared waveband. The 1240 kg mass spacecraft was developed for ESA by a European industrial team led by EADS Astrium with 25 main contractors spread across 14 countries. It lifted off onboard a Soyuz-Fregat rocket, the launch service being provided by Starsem. The lift-off from the Baikonur Cosmodrome in Kazakstan this morning took place at 09:33 hours local time (04:33 Central European Time). Initial Fregat upper-stage ignition took place 9 minutes into the flight, manoeuvring the spacecraft into a low-earth parking orbit. A second firing, 1 hour 22 minutes later, boosted the spacecraft to pursue its interplanetary trajectory. Contact with Venus Express was established by ESA's European Space Operations Centre (ESOC) at Darmstadt, Germany approximately two hours after lift-off. The spacecraft has correctly oriented itself in relation to the sun and has deployed its solar arrays. All onboard systems are operating perfectly and the orbiter is communicating with the Earth via its low-gain antenna. In three days' time, it will establish communications using its high-gain antenna. Full speed ahead for Venus Venus Express is currently distancing itself from the Earth full speed, heading on its five-month 350 million kilometre journey inside our solar system. After check-outs to ensure that its onboard equipment and instrument payload are in proper working order, the spacecraft will be mothballed, with contact with the Earth being

  8. Venus Express en route to probe the planet's hidden mysteries

    NASA Astrophysics Data System (ADS)

    2005-11-01

    Venus Express will eventually manoeuvre itself into orbit around Venus in order to perform a detailed study of the structure, chemistry and dynamics of the planet's atmosphere, which is characterised by extremely high temperatures, very high atmospheric pressure, a huge greenhouse effect and as-yet inexplicable "super-rotation" which means that it speeds around the planet in just four days. The European spacecraft will also be the first orbiter to probe the planet's surface while exploiting the "visibility windows" recently discovered in the infrared waveband. The 1240 kg mass spacecraft was developed for ESA by a European industrial team led by EADS Astrium with 25 main contractors spread across 14 countries. It lifted off onboard a Soyuz-Fregat rocket, the launch service being provided by Starsem. The lift-off from the Baikonur Cosmodrome in Kazakstan this morning took place at 09:33 hours local time (04:33 Central European Time). Initial Fregat upper-stage ignition took place 9 minutes into the flight, manoeuvring the spacecraft into a low-earth parking orbit. A second firing, 1 hour 22 minutes later, boosted the spacecraft to pursue its interplanetary trajectory. Contact with Venus Express was established by ESA's European Space Operations Centre (ESOC) at Darmstadt, Germany approximately two hours after lift-off. The spacecraft has correctly oriented itself in relation to the sun and has deployed its solar arrays. All onboard systems are operating perfectly and the orbiter is communicating with the Earth via its low-gain antenna. In three days' time, it will establish communications using its high-gain antenna. Full speed ahead for Venus Venus Express is currently distancing itself from the Earth full speed, heading on its five-month 350 million kilometre journey inside our solar system. After check-outs to ensure that its onboard equipment and instrument payload are in proper working order, the spacecraft will be mothballed, with contact with the Earth being

  9. Cosmic strings in hidden sectors: 1. Radiation of standard model particles

    SciTech Connect

    Long, Andrew J.; Hyde, Jeffrey M.; Vachaspati, Tanmay E-mail: jmhyde@asu.edu

    2014-09-01

    In hidden sector models with an extra U(1) gauge group, new fields can interact with the Standard Model only through gauge kinetic mixing and the Higgs portal. After the U(1) is spontaneously broken, these interactions couple the resultant cosmic strings to Standard Model particles. We calculate the spectrum of radiation emitted by these ''dark strings'' in the form of Higgs bosons, Z bosons, and Standard Model fermions assuming that string tension is above the TeV scale. We also calculate the scattering cross sections of Standard Model fermions on dark strings due to the Aharonov-Bohm interaction. These radiation and scattering calculations will be applied in a subsequent paper to study the cosmological evolution and observational signatures of dark strings.

  10. Ultrasonic imaging of hidden defects using dry-coupled ultrasonic probes

    NASA Astrophysics Data System (ADS)

    Komsky, Igor N.

    2006-03-01

    Safety criteria of aircraft industry require careful inspection of aircraft components for structural integrity since airworthiness of aging aircraft can be significantly affected by combination of corrosion and fatigue damage. Surface defects can be efficiently detected by visual or other surface inspection techniques. Detection of hidden defects, on the other hand, is still a challenging task. Therefore, it is essential to develop non-destructive methods that can inspect different layers of the aircraft structures for internal defects before they become a safety concern. Ultrasonic probes with the dry-coupled substrates are highly efficient for all modalities of ultrasonic techniques including pulse-echo, pitch-catch, or through-transmission modes. The probes can be deployed in conjunction with portable ultrasonic instruments for B- and C-scanning. The dry-coupled probes have already been tested on a number of aircraft for rapid inspections of the aircraft structures from the outside without any disassembly. However, adequate inspection for small pitting corrosion and incipient fatigue cracks in metallic structures or delaminations in composite panels may require superior sensitivity and resolution of the applied ultrasonic technique. Several novel configurations of the dry-coupled probes with increased sensitivity and resolution will be presented. Ultrasonic imaging with single- or double-element dry-coupled probes will be demonstrated on the specimens with heavy pitting corrosion, machined planar and volumetric defects, and embedded internal flaws.

  11. Neutrino mixing and masses in SO(10) GUTs with hidden sector and flavor symmetries

    NASA Astrophysics Data System (ADS)

    Chu, Xiaoyong; Smirnov, Alexei Yu.

    2016-05-01

    We consider the neutrino masses and mixing in the framework of SO(10) GUTs with hidden sector consisting of fermionic and bosonic SO(10) singlets and flavor symmetries. The framework allows to disentangle the CKM physics responsible for the CKM mixing and different mass hierarchies of quarks and leptons and the neutrino new physics which produces smallness of neutrino masses and large lepton mixing. The framework leads naturally to the relation U PMNS ˜ V CKM † U 0, where structure of U 0 is determined by the flavor symmetry. The key feature of the framework is that apart from the Dirac mass matrices m D , the portal mass matrix M D and the mass matrix of singlets M S are also involved in generation of the lepton mixing. This opens up new possibilities to realize the flavor symmetries and explain the data. Using A 4 × Z 4 as the flavor group, we systematically explore the flavor structures which can be obtained in this framework depending on field content and symmetry assignments. We formulate additional conditions which lead to U 0 ˜ U TBM or U BM. They include (i) equality (in general, proportionality) of the singlet flavons couplings, (ii) equality of their VEVs; (iii) correlation between VEVs of singlets and triplet, (iv) certain VEV alignment of flavon triplet(s). These features can follow from additional symmetries or be remnants of further unification. Phenomenologically viable schemes with minimal flavon content and minimal number of couplings are constructed.

  12. Development of adapted GMR-probes for automated detection of hidden defects in thin steel sheets

    NASA Astrophysics Data System (ADS)

    Pelkner, Matthias; Pohl, Rainer; Kreutzbruck, Marc; Commandeur, Colin

    2016-02-01

    Thin steel sheets with a thickness of 0.3 mm and less are the base materials of many everyday life products (cans, batteries, etc.). Potential inhomogeneities such as non-metallic inclusions inside the steel can lead to a rupture of the sheets when it is formed into a product such as a beverage can. Therefore, there is a need to develop automated NDT techniques to detect hidden defects and inclusions in thin sheets during production. For this purpose Tata Steel Europe and BAM, the Federal Institute for Materials Research and Testing (Germany), collaborate in order to develop an automated NDT-system. Defect detection systems have to be robust against external influences, especially when used in an industrial environment. In addition, such a facility has to achieve a high sensitivity and a high spatial resolution in terms of detecting small inclusions in the μm-regime. In a first step, we carried out a feasibility study to determine which testing method is promising for detecting hidden defects and inclusions inside ferrous thin steel sheets. Therefore, two methods were investigated in more detail - magnetic flux leakage testing (MFL) using giant magneto resistance sensor arrays (GMR) as receivers [1,2] and eddy current testing (ET). The capabilities of both methods were tested with 0.2 mm-thick steel samples containing small defects with depths ranging from 5 µm up to 60 µm. Only in case of GMR-MFL-testing, we were able to detect parts of the hidden defects with a depth of 10 µm trustworthily with a SNR better than 10 dB. Here, the lift off between sensor and surface was 250 µm. On this basis, we investigated different testing scenarios including velocity tests and different lift offs. In this contribution we present the results of the feasibility study leading to first prototypes of GMR-probes which are now installed as part of a demonstrator inside a production line.

  13. Dynamically generated N* and {Lambda}* resonances in the hidden charm sector around 4.3 GeV

    SciTech Connect

    Wu Jiajun; Molina, R.; Oset, E.; Zou, B. S.

    2011-07-15

    The interactions of D-bar{Sigma}{sub c}-D-bar{Lambda}{sub c}, D-bar*{Sigma}{sub c}-D-bar*{Lambda}{sub c}, and related strangeness channels, are studied within the framework of the coupled-channel unitary approach with the local hidden gauge formalism. A series of meson-baryon dynamically generated relatively narrow N* and {Lambda}* resonances are predicted around 4.3 GeV in the hidden charm sector. We make estimates of production cross sections of these predicted resonances in p-barp collisions for the experiment of antiproton annihilation at Darmstadt (PANDA) at the forthcoming GSI Facility for Antiproton and Ion Research (FAIR) facility.

  14. Hidden interactions of sterile neutrinos as a probe for new physics

    NASA Astrophysics Data System (ADS)

    Tabrizi, Zahra; Peres, O. L. G.

    2016-03-01

    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 νsHI model) with mass MX and leptonic coupling gl' . By performing an analysis on the νsHI model using the data of the MINOS neutrino experiment, we find that the values above GX/GF=92.4 are excluded by more than 2 σ C.L., where GF is the Fermi constant and GX is the field strength of the νsHI model. Using this model, we can also probe other new physics scenarios. We find that the region allowed by the (g -2 )μ discrepancy is entirely ruled out for MX≲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 ×10-2 . This exclusion, however, does depend on the value of gl'.

  15. WIMPless dark matter from an anomaly-mediated supersymmetry breaking hidden sector with no new mass parameters

    NASA Astrophysics Data System (ADS)

    Feng, Jonathan L.; Rentala, Vikram; Surujon, Ze'Ev

    2012-03-01

    We present a model with dark matter in an anomaly-mediated supersymmetry breaking hidden sector with a U(1)×U(1) gauge symmetry. The symmetries of the model stabilize the dark matter and forbid the introduction of new mass parameters. As a result, the thermal relic density is completely determined by the gravitino mass and dimensionless couplings. Assuming nonhierarchical couplings, the thermal relic density is ΩX˜0.1, independent of the dark matter’s mass and interaction strength, realizing the WIMPless miracle. The model has several striking features. For particle physics, stability of the dark matter is completely consistent with R-parity violation in the visible sector, with implications for superpartner collider signatures; also the thermal relic’s mass may be ˜10GeV or lighter, which is of interest given recent direct detection results. Interesting astrophysical signatures are dark matter self-interactions through a long-range force, and massless hidden photons and fermions that contribute to the number of relativistic degrees of freedom at big bang nucleosynthesis and cosmic microwave background. The latter are particularly interesting, given current indications for extra degrees of freedom and near future results from the Planck observatory.

  16. Search for Hidden-Sector Bosons in B0→K*0μ+μ- Decays

    NASA Astrophysics Data System (ADS)

    Aaij, R.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Anderson, J.; Andreassi, G.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Aquines Gutierrez, O.; Archilli, F.; d'Argent, P.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Bel, L. J.; Bellee, V.; Belloli, N.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bertolin, A.; Bettler, M.-O.; van Beuzekom, M.; Bien, A.; Bifani, S.; Billoir, P.; Bird, T.; Birnkraut, A.; Bizzeti, A.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borsato, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Braun, S.; Britsch, M.; Britton, T.; Brodzicka, J.; Brook, N. H.; Buchanan, E.; Bursche, A.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Calvo Gomez, M.; Campana, P.; Campora Perez, D.; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carniti, P.; Carson, L.; Carvalho Akiba, K.; Casse, G.; Cassina, L.; Castillo Garcia, L.; Cattaneo, M.; Cauet, Ch.; Cavallero, G.; Cenci, R.; Charles, M.; Charpentier, Ph.; Chefdeville, M.; Chen, S.; Cheung, S.-F.; Chiapolini, N.; Chrzaszcz, M.; Cid Vidal, X.; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collazuol, G.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Corvo, M.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A.; Cruz Torres, M.; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; Dall'Occo, E.; Dalseno, J.; David, P. N. Y.; Davis, A.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Simone, P.; Dean, C.-T.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Déléage, N.; Demmer, M.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; Di Canto, A.; Di Ruscio, F.; Dijkstra, H.; Donleavy, S.; Dordei, F.; Dorigo, M.; Dosil Suárez, A.; Dossett, D.; Dovbnya, A.; Dreimanis, K.; Dufour, L.; Dujany, G.; Dupertuis, F.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; El Rifai, I.; Elsasser, Ch.; Ely, S.; Esen, S.; Evans, H. M.; Evans, T.; Falabella, A.; Färber, C.; Farley, N.; Farry, S.; Fay, R.; Ferguson, D.; Fernandez Albor, V.; Ferrari, F.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fohl, K.; Fol, P.; Fontana, M.; Fontanelli, F.; Forty, R.; Francisco, O.; Frank, M.; Frei, C.; Frosini, M.; Fu, J.; Furfaro, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; García Pardiñas, J.; Garra Tico, J.; Garrido, L.; Gascon, D.; Gaspar, C.; Gauld, R.; Gavardi, L.; Gazzoni, G.; Gerick, D.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianelle, A.; Gianı, S.; Gibson, V.; Girard, O. G.; Giubega, L.; Gligorov, V. V.; Göbel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gotti, C.; Grabalosa Gándara, M.; Graciani Diaz, R.; Granado Cardoso, L. A.; Graugés, E.; Graverini, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Griffith, P.; Grillo, L.; Grünberg, O.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Hadavizadeh, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; He, J.; Head, T.; Heijne, V.; Hennessy, K.; Henrard, P.; Henry, L.; Hernando Morata, J. A.; van Herwijnen, E.; Heß, M.; Hicheur, A.; Hill, D.; Hoballah, M.; Hombach, C.; Hulsbergen, W.; Humair, T.; Hussain, N.; Hutchcroft, D.; Hynds, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jawahery, A.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Kanso, W.; Karacson, M.; Karbach, T. M.; Karodia, S.; Kecke, M.; Kelsey, M.; Kenyon, I. R.; Kenzie, M.; Ketel, T.; Khairullin, E.; Khanji, B.; Khurewathanakul, C.; Klaver, S.; Klimaszewski, K.; Kochebina, O.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Kozeiha, M.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Krzemien, W.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kuonen, A. K.; Kurek, K.; Kvaratskheliya, T.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lanfranchi, G.; Langenbruch, C.; Langhans, B.; Latham, T.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Lees, J.-P.; Lefèvre, R.; Leflat, A.; Lefrançois, J.; Lemos Cid, E.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Likhomanenko, T.; Liles, M.; Lindner, R.; Linn, C.; Lionetto, F.; Liu, B.; Liu, X.; Loh, D.; Longstaff, I.; Lopes, J. H.; Lucchesi, D.; Lucio Martinez, M.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Lusiani, A.; Machefert, F.; Maciuc, F.; Maev, O.; Maguire, K.; Malde, S.; Malinin, A.; Manca, G.; Mancinelli, G.; Manning, P.; Mapelli, A.; Maratas, J.; Marchand, J. F.; Marconi, U.; Marin Benito, C.; Marino, P.; Marks, J.; Martellotti, G.; Martin, M.; Martinelli, M.; Martinez Santos, D.; Martinez Vidal, F.; Martins Tostes, D.; Massafferri, A.; Matev, R.; Mathad, A.; Mathe, Z.; Matteuzzi, C.; Mauri, A.; Maurin, B.; Mazurov, A.; McCann, M.; McCarthy, J.; McNab, A.; McNulty, R.; Meadows, B.; Meier, F.; Meissner, M.; Melnychuk, D.; Merk, M.; Michielin, E.; Milanes, D. A.; Minard, M.-N.; Mitzel, D. S.; Molina Rodriguez, J.; Monroy, I. A.; Monteil, S.; Morandin, M.; Morawski, P.; Mordà, A.; Morello, M. J.; Moron, J.; Morris, A. B.; Mountain, R.; Muheim, F.; Müller, D.; Müller, J.; Müller, K.; Müller, V.; Mussini, M.; Muster, B.; Naik, P.; Nakada, T.; Nandakumar, R.; Nandi, A.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A. D.; Nguyen, T. D.; Nguyen-Mau, C.; Niess, V.; Niet, R.; Nikitin, N.; Nikodem, T.; Ninci, D.; Novoselov, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Ogilvy, S.; Okhrimenko, O.; Oldeman, R.; Onderwater, C. J. G.; Osorio Rodrigues, B.; Otalora Goicochea, J. M.; Otto, A.; Owen, P.; Oyanguren, A.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Pappenheimer, C.; Parkes, C.; Passaleva, G.; Patel, G. D.; Patel, M.; Patrignani, C.; Pearce, A.; Pellegrino, A.; Penso, G.; Pepe Altarelli, M.; Perazzini, S.; Perret, P.; Pescatore, L.; Petridis, K.; Petrolini, A.; Petruzzo, M.; Picatoste Olloqui, E.; Pietrzyk, B.; Pilař, T.; Pinci, D.; Pistone, A.; Piucci, A.; Playfer, S.; Plo Casasus, M.; Poikela, T.; Polci, F.; Poluektov, A.; Polyakov, I.; Polycarpo, E.; Popov, A.; Popov, D.; Popovici, B.; Potterat, C.; Price, E.; Price, J. D.; Prisciandaro, J.; Pritchard, A.; Prouve, C.; Pugatch, V.; Puig Navarro, A.; Punzi, G.; Qian, W.; Quagliani, R.; Rachwal, B.; Rademacker, J. H.; Rama, M.; Rangel, M. S.; Raniuk, I.; Rauschmayr, N.; Raven, G.; Redi, F.; Reichert, S.; Reid, M. M.; dos Reis, A. C.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Rives Molina, V.; Robbe, P.; Rodrigues, A. B.; Rodrigues, E.; Rodriguez Lopez, J. A.; Rodriguez Perez, P.; Roiser, S.; Romanovsky, V.; Romero Vidal, A.; Ronayne, J. W.; Rotondo, M.; Rouvinet, J.; Ruf, T.; Ruiz Valls, P.; Saborido Silva, J. J.; Sagidova, N.; Sail, P.; Saitta, B.; Salustino Guimaraes, V.; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santimaria, M.; Santovetti, E.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmelzer, T.; Schmidt, B.; Schneider, O.; Schopper, A.; Schubiger, M.; Schune, M.-H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Shires, A.; Siddi, B. G.; Silva Coutinho, R.; Silva de Oliveira, L.; Simi, G.; Sirendi, M.; Skidmore, N.; Skillicorn, I.; Skwarnicki, T.; Smith, E.; Smith, E.; Smith, I. T.; Smith, J.; Smith, M.; Snoek, H.; Sokoloff, M. D.; Soler, F. J. P.; Soomro, F.; Souza, D.; Souza De Paula, B.; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Stefkova, S.; Steinkamp, O.; Stenyakin, O.; Stevenson, S.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Sun, L.; Sutcliffe, W.; Swientek, K.; Swientek, S.; Syropoulos, V.; Szczekowski, M.; Szumlak, T.; T'Jampens, S.; Tayduganov, A.; Tekampe, T.; Teklishyn, M.; Tellarini, G.; Teubert, F.; Thomas, C.; Thomas, E.; van Tilburg, J.; Tisserand, V.; Tobin, M.; Todd, J.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Torr, N.; Tournefier, E.; Tourneur, S.; Trabelsi, K.; Tran, M. T.; Tresch, M.; Trisovic, A.; Tsaregorodtsev, A.; Tsopelas, P.; Tuning, N.; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagnoni, V.; Valenti, G.; Vallier, A.; Vazquez Gomez, R.; Vazquez Regueiro, P.; Vázquez Sierra, C.; Vecchi, S.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Vesterinen, M.; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Vilasis-Cardona, X.; Vollhardt, A.; Volyanskyy, D.; Voong, D.; Vorobyev, A.; Vorobyev, V.; Voß, C.; de Vries, J. A.; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wandernoth, S.; Wang, J.; Ward, D. R.; Watson, N. K.; Websdale, D.; Weiden, A.; Whitehead, M.; Wilkinson, G.; Wilkinson, M.; Williams, M.; Williams, M. P.; Williams, M.; Williams, T.; Wilson, F. F.; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wright, S.; Wyllie, K.; Xie, Y.; Xu, Z.; Yang, Z.; Yu, J.; Yuan, X.; Yushchenko, O.; Zangoli, M.; Zavertyaev, M.; Zhang, L.; Zhang, Y.; Zhelezov, A.; Zhokhov, A.; Zhong, L.; Zucchelli, S.; LHCb Collaboration

    2015-10-01

    A search is presented for hidden-sector bosons, χ , produced in the decay B0→K*(892 )0χ , with K*(892 )0→K+π- and χ →μ+μ-. The search is performed using p p -collision data corresponding to 3.0 fb-1 collected with the LHCb detector. No significant signal is observed in the accessible mass range 214 ≤m (χ )≤4350 MeV , and upper limits are placed on the branching fraction product B (B0→K*(892 )0χ )×B (χ →μ+μ-) as a function of the mass and lifetime of the χ boson. These limits are of the order of 1 0-9 for χ lifetimes less than 100 ps over most of the m (χ ) range, and place the most stringent constraints to date on many theories that predict the existence of additional low-mass bosons.

  17. Revisiting scalar quark hidden sector in light of 750-GeV diphoton resonance

    NASA Astrophysics Data System (ADS)

    Chiang, Cheng-Wei; Ibe, Masahiro; Yanagida, Tsutomu T.

    2016-05-01

    We revisit the model of a CP -even singlet scalar resonance proposed in arXiv:1507.02483 , where the resonance appears as the lightest composite state made of scalar quarks participating in hidden strong dynamics. We show that the model can consistently explain the excess of diphoton events with an invariant mass around 750 GeV reported by both the ATLAS and CMS experiments. We also discuss the nature of the charged composite states in the TeV range which accompany to the neutral scalar. Due to inseparability of the dynamical scale and the mass of the resonance, the model also predicts signatures associated with the hidden dynamics such as leptons, jets along with multiple photons at future collider experiments. We also associate the TeV-scale dynamics behind the resonance with an explanation of dark matter.

  18. Probing the hidden Higgs bosons of the Y = 0 triplet- and singlet-extended Supersymmetric Standard Model at the LHC

    NASA Astrophysics Data System (ADS)

    Bandyopadhyay, Priyotosh; Corianò, Claudio; Costantini, Antonio

    2015-12-01

    We investigate the scalar sector in an extension of the Minimal Supersymmetric Standard Model (MSSM) containing a SU(2) Higgs triplet of zero hypercharge and a gauge singlet beside the SU(2) scalar doublets. In particular, we focus on a scenario of this model which allows a light pseudoscalar and/or a scalar below 100 GeV, consistent with the most recent data from the LHC and the earlier data from the LEP experiments. We analyze the exotic decay of the discovered Higgs ( h 125) into two light (hidden) Higgs bosons present in the extension. The latter are allowed by the uncertainties in the Higgs decay h 125 → WW ∗, h 125 → ZZ ∗ and h 125 → γγ. The study of the parameter space for such additional scalars/pseudoscalars decay of the Higgs is performed in the gluon fusion channel. The extra hidden Higgs bosons of the enlarged scalar sector, if they exist, will then decay into lighter fermion paris, i.e., boverline{b} , τ overline{τ} and μ overline{μ} via the mixing with the doublets. A detailed simulation using PYTHIA of the 2 b + 2 τ , ≥ 3 τ , 2 b + 2 μ and 2 τ + 2 μ final states is presented. From our analysis we conclude that, depending on the selected benchmark points, such decay modes can be explored with an integrated luminosity of 25 fb-1 at the LHC at a center of mass energy of 13 TeV.

  19. Infrared radiation emitted due to scanning of a hot spot as a probe of hidden defects

    NASA Astrophysics Data System (ADS)

    Woźny, Mariusz; Maś, Kinga; Prokhorenko, Serhiy; Ploch, Dariusz; Sheregii, E. M.

    2016-05-01

    Specially created subsurface defects in a sample are detected using a high resolution infrared camera FLIR SC7000. A scanning hot air (about 110 °C) nozzle is applied to introduce additional energy in a researched sample. The hidden defect has an increased temperature in comparison with the surrounding area that is a result of changed emissivity and thermal diffusivity. The suggested method is compared with pulse thermography which uses a xenon lamp for excitation.

  20. Search for Hidden-Sector Bosons in B(0)→K(*0)μ(+)μ(-) Decays.

    PubMed

    Aaij, R; Adeva, B; Adinolfi, M; Affolder, A; Ajaltouni, Z; Akar, S; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amerio, S; Amhis, Y; An, L; Anderlini, L; Anderson, J; Andreassi, G; Andreotti, M; Andrews, J E; Appleby, R B; Aquines Gutierrez, O; Archilli, F; d'Argent, P; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Bachmann, S; Back, J J; Badalov, A; Baesso, C; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Batozskaya, V; Battista, V; Bay, A; Beaucourt, L; Beddow, J; Bedeschi, F; Bediaga, I; Bel, L J; Bellee, V; Belloli, N; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bertolin, A; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Billoir, P; Bird, T; Birnkraut, A; Bizzeti, A; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borsato, M; Bowcock, T J V; Bowen, E; Bozzi, C; Braun, S; Britsch, M; Britton, T; Brodzicka, J; Brook, N H; Buchanan, E; Bursche, A; Buytaert, J; Cadeddu, S; Calabrese, R; Calvi, M; Calvo Gomez, M; Campana, P; Campora Perez, D; Capriotti, L; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carniti, P; Carson, L; Carvalho Akiba, K; Casse, G; Cassina, L; Castillo Garcia, L; Cattaneo, M; Cauet, Ch; Cavallero, G; Cenci, R; Charles, M; Charpentier, Ph; Chefdeville, M; Chen, S; Cheung, S-F; Chiapolini, N; Chrzaszcz, M; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coco, V; Cogan, J; Cogneras, E; Cogoni, V; Cojocariu, L; Collazuol, G; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Corvo, M; Couturier, B; Cowan, G A; Craik, D C; Crocombe, A; Cruz Torres, M; Cunliffe, S; Currie, R; D'Ambrosio, C; Dall'Occo, E; Dalseno, J; David, P N Y; Davis, A; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Simone, P; Dean, C-T; Decamp, D; Deckenhoff, M; Del Buono, L; Déléage, N; Demmer, M; Derkach, D; Deschamps, O; Dettori, F; Dey, B; Di Canto, A; Di Ruscio, F; Dijkstra, H; Donleavy, S; Dordei, F; Dorigo, M; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dreimanis, K; Dufour, L; Dujany, G; Dupertuis, F; Durante, P; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Ely, S; Esen, S; Evans, H M; Evans, T; Falabella, A; Färber, C; Farley, N; Farry, S; Fay, R; Ferguson, D; Fernandez Albor, V; Ferrari, F; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fiorini, M; Firlej, M; Fitzpatrick, C; Fiutowski, T; Fohl, K; Fol, P; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Fu, J; Furfaro, E; Gallas Torreira, A; Galli, D; Gallorini, S; Gambetta, S; Gandelman, M; Gandini, P; Gao, Y; García Pardiñas, J; Garra Tico, J; Garrido, L; Gascon, D; Gaspar, C; Gauld, R; Gavardi, L; Gazzoni, G; Gerick, D; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gianelle, A; Gianì, S; Gibson, V; Girard, O G; Giubega, L; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gotti, C; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graverini, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Griffith, P; Grillo, L; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadavizadeh, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hamilton, B; Han, X; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; He, J; Head, T; Heijne, V; Hennessy, K; Henrard, P; Henry, L; Hernando Morata, J A; van Herwijnen, E; Heß, M; Hicheur, A; Hill, D; Hoballah, M; Hombach, C; Hulsbergen, W; Humair, T; Hussain, N; Hutchcroft, D; Hynds, D; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jalocha, J; Jans, E; Jawahery, A; Jing, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Jurik, N; Kandybei, S; Kanso, W; Karacson, M; Karbach, T M; Karodia, S; Kecke, M; Kelsey, M; Kenyon, I R; Kenzie, M; Ketel, T; Khairullin, E; Khanji, B; Khurewathanakul, C; Klaver, S; Klimaszewski, K; Kochebina, O; Kolpin, M; Komarov, I; Koopman, R F; Koppenburg, P; Kozeiha, M; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Krzemien, W; Kucewicz, W; Kucharczyk, M; Kudryavtsev, V; Kuonen, A K; Kurek, K; Kvaratskheliya, T; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lanfranchi, G; Langenbruch, C; Langhans, B; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Lemos Cid, E; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Likhomanenko, T; Liles, M; Lindner, R; Linn, C; Lionetto, F; Liu, B; Liu, X; Loh, D; Longstaff, I; Lopes, J H; Lucchesi, D; Lucio Martinez, M; Luo, H; Lupato, A; Luppi, E; Lupton, O; Lusiani, A; Machefert, F; Maciuc, F; Maev, O; Maguire, K; Malde, S; Malinin, A; Manca, G; Mancinelli, G

    2015-10-16

    A search is presented for hidden-sector bosons, χ, produced in the decay B(0)→K*(892)(0)χ, with K*(892)(0)→K(+)π(-) and χ→μ(+)μ(-). The search is performed using pp-collision data corresponding to 3.0  fb(-1) collected with the LHCb detector. No significant signal is observed in the accessible mass range 214≤m(χ)≤4350  MeV, and upper limits are placed on the branching fraction product B(B(0)→K*(892)(0)χ)×B(χ→μ(+)μ(-)) as a function of the mass and lifetime of the χ boson. These limits are of the order of 10(-9) for χ lifetimes less than 100 ps over most of the m(χ) range, and place the most stringent constraints to date on many theories that predict the existence of additional low-mass bosons. PMID:26550866

  1. Galactic center γ-ray excess in hidden sector DM models with dark gauge symmetries: local Z{sub 3} symmetry as an example

    SciTech Connect

    Ko, P.; Tang, Yong

    2015-01-16

    We show that hidden sector dark matter (DM) models with local dark gauge symmetries make a natural playground for the possible γ-ray excess from the galactic center (GC). We first discuss in detail the GC γ-ray excess in a scalar dark matter (DM) model with local Z{sub 3} symmetry which was recently proposed by the present authors. Within this model, scalar DM with mass 30–70 GeV is allowed due to the newly-opened (semi-)annihilation channels of a DM pair into dark Higgs ϕ and/or dark photon Z′ pair, and the γ-ray spectrum from the GC can be fit within this model. Then we argue that the GC gamma ray excess can be easily accommodated within hidden sector dark matter models where DM is stabilized by local gauge symmetries, due to the presence of dark Higgs (and also dark photon for Abelian dark gauge symmetry)

  2. Galactic center γ-ray excess in hidden sector DM models with dark gauge symmetries: local Z{sub 3} symmetry as an example

    SciTech Connect

    Ko, P.; Tang, Yong E-mail: ytang@kias.re.kr

    2015-01-01

    We show that hidden sector dark matter (DM) models with local dark gauge symmetries make a natural playground for the possible γ-ray excess from the galactic center (GC). We first discuss in detail the GC γ-ray excess in a scalar dark matter (DM) model with local Z{sub 3} symmetry which was recently proposed by the present authors. Within this model, scalar DM with mass 30–70 GeV is allowed due to the newly-opened (semi-)annihilation channels of a DM pair into dark Higgs φ and/or dark photon Z' pair, and the γ-ray spectrum from the GC can be fit within this model. Then we argue that the GC gamma ray excess can be easily accommodated within hidden sector dark matter models where DM is stabilized by local gauge symmetries, due to the presence of dark Higgs (and also dark photon for Abelian dark gauge symmetry)

  3. Probing the Dark Sector with Dark Matter Bound States

    NASA Astrophysics Data System (ADS)

    An, Haipeng; Echenard, Bertrand; Pospelov, Maxim; Zhang, Yue

    2016-04-01

    A model of the dark sector where O (few GeV ) mass dark matter particles χ couple to a lighter dark force mediator V , mV≪mχ, is motivated by the recently discovered mismatch between simulated and observed shapes of galactic halos. Such models, in general, provide a challenge for direct detection efforts and collider searches. We show that for a large range of coupling constants and masses, the production and decay of the bound states of χ , such as 0-+ and 1-- states, ηD and ϒD, is an important search channel. We show that e+e-→ηD+V or ϒD+γ production at B factories for αD>0.1 is sufficiently strong to result in multiple pairs of charged leptons and pions via ηD→2 V →2 (l+l-) and ϒD→3 V →3 (l+l-) (l =e ,μ ,π ). The absence of such final states in the existing searches performed at BABAR and Belle sets new constraints on the parameter space of the model. We also show that a search for multiple bremsstrahlung of dark force mediators, e+e-→χ χ ¯+n V , resulting in missing energy and multiple leptons, will further improve the sensitivity to self-interacting dark matter.

  4. Probing the Dark Sector with Dark Matter Bound States.

    PubMed

    An, Haipeng; Echenard, Bertrand; Pospelov, Maxim; Zhang, Yue

    2016-04-15

    A model of the dark sector where O(few  GeV) mass dark matter particles χ couple to a lighter dark force mediator V, m_{V}≪m_{χ}, is motivated by the recently discovered mismatch between simulated and observed shapes of galactic halos. Such models, in general, provide a challenge for direct detection efforts and collider searches. We show that for a large range of coupling constants and masses, the production and decay of the bound states of χ, such as 0^{-+} and 1^{--} states, η_{D} and ϒ_{D}, is an important search channel. We show that e^{+}e^{-}→η_{D}+V or ϒ_{D}+γ production at B factories for α_{D}>0.1 is sufficiently strong to result in multiple pairs of charged leptons and pions via η_{D}→2V→2(l^{+}l^{-}) and ϒ_{D}→3V→3(l^{+}l^{-}) (l=e,μ,π). The absence of such final states in the existing searches performed at BABAR and Belle sets new constraints on the parameter space of the model. We also show that a search for multiple bremsstrahlung of dark force mediators, e^{+}e^{-}→χχ[over ¯]+nV, resulting in missing energy and multiple leptons, will further improve the sensitivity to self-interacting dark matter. PMID:27127956

  5. A framework to analyze searches for gauge bosons of the hidden light sector in electron scattering fixed target experiments

    SciTech Connect

    Beranek, T.

    2013-11-07

    Electron scattering fixed target experiments are a versatile tool to probe various kinds of physics phenomena. Recently fixed target experiments in which an electron beam is scattered off a heavy nucleus and a lepton-antilepton pair is created, i.e. e(A,Z) →e(A,Z)l{sup +}l{sup −}, were utilized to search for physics beyond the standard model at modest energies. In these experiments one searches for a small, narrow resonance in the invariant mass spectrum of the lepton-antilepton pair, arising from the exchange of a new light gauge boson γ′ coupling to the dark sector as well as very weakly to standard model particles. Such a signal would appear as an enhancement over a smooth QED background. Hence a precise understanding of the background is crucial. We present a theoretical analysis of the process e(A,Z) →e(A,Z)l{sup +}l{sup −}. Therefore we have performed an analysis of the cross section, which is then used to extract exclusion limits on the parameter space of the γ′, describing the existing experimental data taken at MAMI.

  6. Gravitational waves as a probe of extended scalar sectors with the first order electroweak phase transition

    NASA Astrophysics Data System (ADS)

    Kakizaki, Mitsuru; Kanemura, Shinya; Matsui, Toshinori

    2015-12-01

    We discuss spectra of gravitational waves which are originated by the strongly first order phase transition at the electroweak symmetry breaking, which is required for a successful scenario of electroweak baryogenesis. Such spectra are numerically evaluated without high temperature expansion in a set of extended scalar sectors with additional N isospin-singlet fields as a concrete example of renormalizable theories. We find that the produced gravitational waves can be significant, so that they are detectable at future gravitational wave interferometers such as DECIGO and BBO. Furthermore, since the spectra strongly depend on N and the mass of the singlet fields, our results indicate that future detailed observation of gravitational waves can be in general a useful probe of extended scalar sectors with the first order phase transition.

  7. Strategies for probing nonminimal dark sectors at colliders: The interplay between cuts and kinematic distributions

    NASA Astrophysics Data System (ADS)

    Dienes, Keith R.; Su, Shufang; Thomas, Brooks

    2015-03-01

    In this paper, we examine the strategies and prospects for distinguishing between traditional dark-matter models and models with nonminimal dark sectors—including models of Dynamical Dark Matter—at hadron colliders. For concreteness, we focus on events with two hadronic jets and large missing transverse energy at the Large Hadron Collider (LHC). As we discuss, simple "bump-hunting" searches are not sufficient; probing nonminimal dark sectors typically requires an analysis of the actual shapes of the distributions of relevant kinematic variables. We therefore begin by identifying those kinematic variables whose distributions are particularly suited to this task. However, as we demonstrate, this then leads to a number of additional subtleties, since cuts imposed on the data for the purpose of background reduction can at the same time have the unintended consequence of distorting these distributions in unexpected ways, thereby obscuring signals of new physics. We therefore proceed to study the correlations between several of the most popular relevant kinematic variables currently on the market, and investigate how imposing cuts on one or more of these variables can impact the distributions of others. Finally, we combine our results in order to assess the prospects for distinguishing nonminimal dark sectors in this channel at the upgraded LHC.

  8. Fermi Surface Reconstruction inside the Hidden Order Phase of URu2Si2 Probed by Thermoelectric Measurements

    NASA Astrophysics Data System (ADS)

    Pourret, Alexandre; Palacio-Morales, Alexandra; Krämer, Steffen; Malone, Liam; Nardone, Marc; Aoki, Dai; Knebel, Georg; Flouquet, Jacques

    2013-03-01

    We report thermoelectric measurements of the low carrier heavy fermion compound URu2Si2 at high fields up to 34 T and at low temperatures down to 500 mK. The field dependence of the thermoelectric power (TEP) and the Nernst signal shows successive anomalies deep inside the hidden order (HO) phase. The field position of these anomalies correspond to different changes in the Shubnikov--de Haas frequencies and effective masses around 12, 17, 23, and 30 T. These results indicate successive reconstructions of the Fermi surface, which imply electronic phase transitions well within the HO phase.

  9. Probing the Higgs sector of high-scale supersymmetry-breaking models at the Tevatron

    SciTech Connect

    Carena, Marcela; Draper, Patrick; Heinemeyer, Sven; Liu, Tao; Wagner, Carlos E. M.; Weiglein, Georg

    2011-03-01

    A canonical signature of the minimal supersymmetric standard model (MSSM) is the presence of a neutral Higgs boson with mass bounded from above by about 135 GeV and standard model (SM)-like couplings to the electroweak gauge bosons. In this paper we investigate the reach of the Tevatron collider for the MSSM Higgs sector parameter space associated with a variety of high-scale minimal models of supersymmetry (SUSY) breaking, including the constrained MSSM, minimal gauge-mediated SUSY breaking, and minimal anomaly-mediated SUSY breaking. We find that the Tevatron can provide strong constraints on these models via Higgs boson searches. Considering a simple projection for the efficiency improvements in the Tevatron analyses, we find that with an integrated luminosity of 16 fb{sup -1} per detector and an efficiency improvement of 20% compared to the present situation, these models could be probed essentially over their entire ranges of validity. With 40% analysis improvements and 16 fb{sup -1}, our projection shows that evidence at the 3{sigma} level for the light Higgs boson could be expected in extended regions of parameter space.

  10. Probing the Higgs sector of high-scale supersymmetry-breaking models at the Tevatron.

    SciTech Connect

    Carena, M.; Draper, P.; Heinemeyer, S.; Liu, T.; Wagner, C. E. M.; Weiglein, G.

    2011-03-07

    A canonical signature of the minimal supersymmetric standard model (MSSM) is the presence of a neutral Higgs boson with mass bounded from above by about 135 GeV and standard model (SM)-like couplings to the electroweak gauge bosons. In this paper we investigate the reach of the Tevatron collider for the MSSM Higgs sector parameter space associated with a variety of high-scale minimal models of supersymmetry (SUSY) breaking, including the constrained MSSM, minimal gauge-mediated SUSY breaking, and minimal anomaly-mediated SUSY breaking. We find that the Tevatron can provide strong constraints on these models via Higgs boson searches. Considering a simple projection for the efficiency improvements in the Tevatron analyses, we find that with an integrated luminosity of 16 fb{sup -1} per detector and an efficiency improvement of 20% compared to the present situation, these models could be probed essentially over their entire ranges of validity. With 40% analysis improvements and 16 fb{sup -1}, our projection shows that evidence at the 3{sigma} level for the light Higgs boson could be expected in extended regions of parameter space.

  11. Apatite as probe for the halogen composition of metamorphic fluids (Bamble Sector, SE Norway)

    NASA Astrophysics Data System (ADS)

    Kusebauch, Christof; John, Timm; Whitehouse, Martin J.; Engvik, Ane K.

    2015-10-01

    Halogen composition of replaced apatite formed during a regional metasomatic event (Bamble Sector, SE Norway) reveals information about the composition and evolution of the hydrothermal fluid. Infiltration and pervasive fluid flow of highly saline fluids into gabbroic bodies lead to scapolitization and amphibolitization, where magmatic Cl-rich apatite reacts with the hydrothermal fluid to form OH- and/or F-rich apatite. Apatite from highly altered samples adjacent to the shear zone has highest F (up to 15,000 µg/g) and lowest Br (4-25 µg/g) concentrations, whereas apatite from least altered samples has very low F (30-200 µg/g) and high Br (30-85 µg/g). In addition, individual replaced apatite grains show a zonation in F with high concentrations along rims and cracks and low F in core regions. Iodine concentrations remain rather constant as low values of 0.18-0.70 µg/g. We interpret all observed compositional features of replaced apatite to be the result of a continuous evolution of the fluid during fluid-rock interaction. Due to its high compatibility, F from the infiltrating fluid is incorporated early into recrystallized apatite (close to shear zone and rims of individual apatite grains). In contrast, Br as an incompatible halogen becomes enriched in the fluid and is highest in the most evolved fluid. Using experimental partition data between replaced apatite and fluid, we calculated F concentrations of the evolving fluid to decrease from 60 to <1 µg/g and Br to increase from ~1200 to ~5000 µg/g; I concentrations of the fluid are constant in the order of 370 µg/g. Although Cl is expected to show a similar behavior as Br, replaced apatite has constant Cl concentrations throughout the alteration sequence (~1 wt.%), which is likely the result of a rather constant Cl activity in the fluid. Chlorine stable isotope values of individual apatite grains are heterogeneous and range from -1.2 to +3.7 ‰. High δ 37Cl values are generally correlated with OH

  12. STELLAR MASS-GAP AS A PROBE OF HALO ASSEMBLY HISTORY AND CONCENTRATION: YOUTH HIDDEN AMONG OLD FOSSILS

    SciTech Connect

    Deason, A. J.; Conroy, C.; Wetzel, A. R.; Tinker, J. L.

    2013-11-10

    We investigate the use of the halo mass-gap statistic—defined as the logarithmic difference in mass between the host halo and its most massive satellite subhalo—as a probe of halo age and concentration. A cosmological N-body simulation is used to study N ∼ 25, 000 group/cluster-sized halos in the mass range 10{sup 12.5} < M{sub halo}/M{sub ☉} < 10{sup 14.5}. In agreement with previous work, we find that halo mass-gap is related to halo formation time and concentration. On average, older and more highly concentrated halos have larger halo mass-gaps, and this trend is stronger than the mass-concentration relation over a similar dynamic range. However, there is a large amount of scatter owing to the transitory nature of the satellite subhalo population, which limits the use of the halo mass-gap statistic on an object-by-object basis. For example, we find that 20% of very large halo mass-gap systems (akin to {sup f}ossil groups{sup )} are young and have likely experienced a recent merger between a massive satellite subhalo and the central subhalo. We relate halo mass-gap to the observable stellar mass-gap via abundance matching. Using a galaxy group catalog constructed from the Sloan Digital Sky Survey Data Release 7, we find that the star formation and structural properties of galaxies at fixed mass show no trend with stellar mass-gap. This is despite a variation in halo age of ≈2.5 Gyr over ≈1.2 dex in stellar mass-gap. Thus, we find no evidence to suggest that the halo formation history significantly affects galaxy properties.

  13. Gauge extensions of supersymmetric models and hidden valleys

    NASA Astrophysics Data System (ADS)

    Luo, Mingxing; Zheng, Sibo

    2009-04-01

    Supersymmetric models with extended group structure beyond the standard model are revisited in the framework of general gauge mediation. Sum rules for sfermion masses are shown to depend genuinely on the group structure, which can serve as important probes for specific models. The left-right model and models with extra U(1) are worked out for illustrations. If the couplings of extra gauge groups are small, supersymmetric hidden valleys of the scale 10-100 GeV can be naturally constructed in companion of a TeV-scale supersymmetric visible sector.

  14. A Magnified Glance into the Dark Sector: Probing Cosmological Models with Strong Lensing in A1689

    NASA Astrophysics Data System (ADS)

    Magaña, Juan; Cárdenas, V. Motta ´ctor H., Vi; Verdugo, T.; Jullo, Eric

    2015-11-01

    In this paper we constrain four alternative models to the late cosmic acceleration in the universe: Chevallier–Polarski–Linder (CPL), interacting dark energy (IDE), Ricci holographic dark energy (HDE), and modified polytropic Cardassian (MPC). Strong lensing (SL) images of background galaxies produced by the galaxy cluster Abell 1689 are used to test these models. To perform this analysis we modify the LENSTOOL lens modeling code. The value added by this probe is compared with other complementary probes: Type Ia supernovae (SN Ia), baryon acoustic oscillations (BAO), and cosmic microwave background (CMB). We found that the CPL constraints obtained for the SL data are consistent with those estimated using the other probes. The IDE constraints are consistent with the complementary bounds only if large errors in the SL measurements are considered. The Ricci HDE and MPC constraints are weak, but they are similar to the BAO, SN Ia, and CMB estimations. We also compute the figure of merit as a tool to quantify the goodness of fit of the data. Our results suggest that the SL method provides statistically significant constraints on the CPL parameters but is weak for those of the other models. Finally, we show that the use of the SL measurements in galaxy clusters is a promising and powerful technique to constrain cosmological models. The advantage of this method is that cosmological parameters are estimated by modeling the SL features for each underlying cosmology. These estimations could be further improved by SL constraints coming from other galaxy clusters.

  15. Channel probe measurements for the American Sector Clutter Experiment, January 1994

    NASA Astrophysics Data System (ADS)

    Fitzgerald, T. J.

    1994-05-01

    The ionospheric phenomenon called Equatorial Spread F encompasses a variety of effects associated with plasma irregularities occurring in the post-sunset and nighttime ionosphere near the magnetic equator. These irregularities can seriously degrade the performance of systems which involve either of necessity or inadvertently radio propagation through the equatorial ionosphere. One such system is Over-the-Horizon (OTH) radars which operate in the high-frequency (hf) band and use ionospheric reflection for forward and backscatter propagation to ranges of thousands of kilometers. When such radars are directed towards the equator, Spread F irregularities can cause scintillation effects which may be aliased into the ranges of interest and have the effect of causing, excess clutter in which targets may be hidden. In January, 1994 Los Alamos participated in a campaign to measure Spread F effects on OTH propagation from the United States looking towards South America in conjunction with local diagnostics in Peru. During the campaign Los Alamos fielded a 1600 km bistatic path between Piura, Peru, and Arequipa, Peru, the one-hop reflection region for this path was near the magnetic equator. We obtained four types of measurements: an oblique ionogram between Piura and Arequipa every three minutes; Doppler spread and spatial correlation for a single frequency cw path between Piura and Arequipa; Doppler spread, time-delay spread, and spatial coherence for a 10 kHz bandwidth path between Piura and Arequipa, and Doppler spread and time-delay spread for the one-way path between the AVA radar in New York and Arequipa, Peru. This report describes the diagnostic experiments that we carried out and gives a brief description of some of the data we obtained.

  16. Channel probe measurements for the American sector clutter experiment, January, 1994

    SciTech Connect

    Fitzgerald, T.J.

    1994-05-20

    The ionospheric phenomenon called Equatorial Spread F encompasses a variety of effects associated with plasma irregularities occurring in the post-sunset and nighttime ionosphere near the magnetic equator. These irregularities can seriously degrade the performance of systems which involve either of necessity or inadvertently radio propagation through the equatorial ionosphere. One such system is Over-the-Horizon (OTH) radars which operate in the high-frequency (hf) band and use ionospheric reflection for forward and backscatter propagation to ranges of thousands of kilometers. When such radars are directed towards the equator, Spread F irregularities can cause scintillation effects which may be aliased into the ranges of interest and have the effect of causing, excess clutter in which targets may be hidden. In January, 1994 Los Alamos participated in a campaign to measure Spread F effects on OTH propagation from the United States looking towards South America in conjunction with local diagnostics in Peru. During the campaign Los Alamos fielded a 1600 km bistatic path between Piura, Peru, and Arequipa, Peru-, the one-hop reflection region for this path was near the magnetic equator, We obtained four types of measurements: an oblique ionogram between Piura and Arequipa every three minutes; Doppler spread and spatial correlation for a single frequency cw path between Piura and Arequipa; Doppler spread, time-delay spread, and spatial coherence for a 10 kHz bandwidth path between Piura and Arequipa-, and Doppler spread and time-delay spread for the one-way path between the AVA radar in New York and Arequipa, Peru. This report describes the diagnostic experiments that we carried out and gives a brief description of some of the data we obtained.

  17. Hidden conformal symmetry of extremal black holes

    SciTech Connect

    Chen Bin; Long Jiang; Zhang Jiaju

    2010-11-15

    We study the hidden conformal symmetry of extremal black holes. We introduce a new set of conformal coordinates to write the SL(2,R) generators. We find that the Laplacian of the scalar field in many extremal black holes, including Kerr(-Newman), Reissner-Nordstrom, warped AdS{sub 3}, and null warped black holes, could be written in terms of the SL(2,R) quadratic Casimir. This suggests that there exist dual conformal field theory (CFT) descriptions of these black holes. From the conformal coordinates, the temperatures of the dual CFTs could be read directly. For the extremal black hole, the Hawking temperature is vanishing. Correspondingly, only the left (right) temperature of the dual CFT is nonvanishing, and the excitations of the other sector are suppressed. In the probe limit, we compute the scattering amplitudes of the scalar off the extremal black holes and find perfect agreement with the CFT prediction.

  18. Hidden earthquakes

    SciTech Connect

    Stein, R.S.; Yeats, R.S.

    1989-06-01

    Seismologists generally look for earthquakes to happen along visible fault lines, e.g., the San Andreas fault. The authors maintain that another source of dangerous quakes has been overlooked: the release of stress along a fault that is hidden under a fold in the earth's crust. The paper describes the differences between an earthquake which occurs on a visible fault and one which occurs under an anticline and warns that Los Angeles greatest earthquake threat may come from a small quake originating under downtown Los Angeles, rather than a larger earthquake which occurs 50 miles away at the San Andreas fault.

  19. Isovector and hidden-beauty partners of the X(3872)

    NASA Astrophysics Data System (ADS)

    Høgaasen, Hallstein; Kou, Emi; Richard, Jean-Marc; Sorba, Paul

    2014-05-01

    The isovector partners of the X(3872), recently found at BES III, Belle and CLEO-c were predicted in a simple model based on the chromomagnetic interaction among quarks. The extension to the hidden-beauty sector is discussed.

  20. Herschel observations of extra-ordinary sources: H{sub 2}S as a probe of dense gas and possibly hidden luminosity toward the Orion KL hot core

    SciTech Connect

    Crockett, N. R.; Bergin, E. A.; Neill, J. L.; Black, J. H.; Blake, G. A.; Kleshcheva, M.

    2014-02-01

    We present Herschel/HIFI observations of the light hydride H{sub 2}S obtained from the full spectral scan of the Orion Kleinmann-Low nebula (Orion KL) taken as part of the Herschel Observations of EXtra-Ordinary Sources GT (guaranteed time) key program. In total, we observe 52, 24, and 8 unblended or slightly blended features from H{sub 2} {sup 32}S, H{sub 2} {sup 34}S, and H{sub 2} {sup 33}S, respectively. We only analyze emission from the so-called hot core, but emission from the plateau, extended ridge, and/or compact ridge are also detected. Rotation diagrams for ortho and para H{sub 2}S follow straight lines given the uncertainties and yield T {sub rot} = 141 ± 12 K. This indicates H{sub 2}S is in local thermodynamic equilibrium and is well characterized by a single kinetic temperature or an intense far-IR radiation field is redistributing the population to produce the observed trend. We argue the latter scenario is more probable and find that the most highly excited states (E {sub up} ≳ 1000 K) are likely populated primarily by radiation pumping. We derive a column density, N {sub tot}(H{sub 2} {sup 32}S) = 9.5 ± 1.9 × 10{sup 17} cm{sup –2}, gas kinetic temperature, T {sub kin} = 120±{sub 10}{sup 13} K, and constrain the H{sub 2} volume density, n{sub H{sub 2}} ≳ 9 × 10 {sup 7} cm{sup –3}, for the H{sub 2}S emitting gas. These results point to an H{sub 2}S origin in markedly dense, heavily embedded gas, possibly in close proximity to a hidden self-luminous source (or sources), which are conceivably responsible for Orion KL's high luminosity. We also derive an H{sub 2}S ortho/para ratio of 1.7 ± 0.8 and set an upper limit for HDS/H{sub 2}S of <4.9 × 10 {sup –3}.

  1. Herschel Observations of EXtra-Ordinary Sources: H2S as a Probe of Dense Gas and Possibly Hidden Luminosity Toward the Orion KL Hot Core

    NASA Astrophysics Data System (ADS)

    Crockett, N. R.; Bergin, E. A.; Neill, J. L.; Black, J. H.; Blake, G. A.; Kleshcheva, M.

    2014-02-01

    We present Herschel/HIFI observations of the light hydride H2S obtained from the full spectral scan of the Orion Kleinmann-Low nebula (Orion KL) taken as part of the Herschel Observations of EXtra-Ordinary Sources GT (guaranteed time) key program. In total, we observe 52, 24, and 8 unblended or slightly blended features from H2 32S, H2 34S, and H2 33S, respectively. We only analyze emission from the so-called hot core, but emission from the plateau, extended ridge, and/or compact ridge are also detected. Rotation diagrams for ortho and para H2S follow straight lines given the uncertainties and yield T rot = 141 ± 12 K. This indicates H2S is in local thermodynamic equilibrium and is well characterized by a single kinetic temperature or an intense far-IR radiation field is redistributing the population to produce the observed trend. We argue the latter scenario is more probable and find that the most highly excited states (E up >~ 1000 K) are likely populated primarily by radiation pumping. We derive a column density, N tot(H2 32S) = 9.5 ± 1.9 × 1017 cm-2, gas kinetic temperature, T kin = 120+/- ^{13}_{10} K, and constrain the H2 volume density, n_H_2 >~ 9 × 10 7 cm-3, for the H2S emitting gas. These results point to an H2S origin in markedly dense, heavily embedded gas, possibly in close proximity to a hidden self-luminous source (or sources), which are conceivably responsible for Orion KL's high luminosity. We also derive an H2S ortho/para ratio of 1.7 ± 0.8 and set an upper limit for HDS/H2S of <4.9 × 10 -3. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  2. Hunting for the Xb via hidden bottomonium decays

    NASA Astrophysics Data System (ADS)

    Li, Gang; Zhou, Zhu

    2015-02-01

    In this work, we study the isospin conserved hidden bottomonium decay of Xb→ϒ (1 S )ω , where Xb is taken to be the counterpart of the famous X (3872 ) in the bottomonium sector as a candidate for the meson-meson molecule. Since it is likely that the Xb is below the B B¯* threshold and the mass difference between the neutral and charged bottom meson is small compared to the binding energy of the Xb, the isospin violating decay mode Xb→ϒ (n S )π+π- would be greatly suppressed. We use the effective Lagrangian based on the heavy quark symmetry to explore the rescattering mechanism of Xb→ϒ (1 S )ω and calculate the partial widths. Our results show that the partial width for the Xb→ϒ (1 S )ω is about tens of keVs. Taking into account the fact that the total width of Xb may be smaller than a few MeV like X (3872 ), the calculated branching ratios may reach to orders of 10-2. These hidden bottomonium decay modes are of great importance in the experimental search for the Xb particularly at the hadron collider. Also, the associated studies of hidden bottomonium decays Xb→ϒ (n S )γ , ϒ (n S )ω , and B B ¯γ may help us investigate the structure of Xb deeply. The experimental observation of Xb will provide us with further insight into the spectroscopy of exotic states and is helpful to probe the structure of the states connected by the heavy quark symmetry.

  3. Signatures of a hidden cosmic microwave background.

    PubMed

    Jaeckel, Joerg; Redondo, Javier; Ringwald, Andreas

    2008-09-26

    If there is a light Abelian gauge boson gamma' in the hidden sector its kinetic mixing with the photon can produce a hidden cosmic microwave background (HCMB). For meV masses, resonant oscillations gamma<-->gamma' happen after big bang nucleosynthesis (BBN) but before CMB decoupling, increasing the effective number of neutrinos Nnu(eff) and the baryon to photon ratio, and distorting the CMB blackbody spectrum. The agreement between BBN and CMB data provides new constraints. However, including Lyman-alpha data, Nnu(eff) > 3 is preferred. It is tempting to attribute this effect to the HCMB. The interesting parameter range will be tested in upcoming laboratory experiments. PMID:18851438

  4. Problem of hidden variables

    NASA Astrophysics Data System (ADS)

    Santos, Emilio

    1992-10-01

    The problem of hidden variables in quantum mechanics is formalized as follows. A general or contextual (noncontextual) hidden-variables theory is defined as a mapping f: Q×M → C (f: Q→C) where Q is the set of projection operators in the appropriate (quantum) Hilbert space, M is the set of maximal Boolean subalgebras of Q and C is a (classical) Boolean algebra. It is shown that contextual (noncontextual) hidden-variables always exist (do not exist).

  5. Friedel oscillations: Decoding the hidden physics

    NASA Astrophysics Data System (ADS)

    Bena, Cristina

    2016-03-01

    We show that the impurity-induced Friedel oscillations allow one to probe in an unexpected and quite remarkable manner the electronic properties of two-dimensional systems such as graphene or high-temperature superconductors. In particular, we show that by studying these oscillations, one can get access not only to the constant-energy maps, but also to more hidden information such as the chiral properties of Dirac electrons in graphene, which cannot be observed directly by other methods. For graphene, this hidden information is revealed by comparing the theoretical predictions with scanning tunneling microscopy experimental measurements of the local density of states. xml:lang="fr"

  6. Hidden SU (N ) glueball dark matter

    NASA Astrophysics Data System (ADS)

    Soni, Amarjit; Zhang, Yue

    2016-06-01

    We investigate the possibility that the dark matter candidate is from a pure non-Abelian gauge theory of the hidden sector, motivated in large part by its elegance and simplicity. The dark matter is the lightest bound state made of the confined gauge fields, the hidden glueball. We point out that this simple setup is capable of providing rich and novel phenomena in the dark sector, especially in the parameter space of large N . They include self-interacting and warm dark matter scenarios, Bose-Einstein condensation leading to massive dark stars possibly millions of times heavier than our sun giving rise to gravitational lensing effects, and indirect detections through higher dimensional operators as well as interesting collider signatures.

  7. Dark matter freeze-out in a nonrelativistic sector

    NASA Astrophysics Data System (ADS)

    Pappadopulo, Duccio; Ruderman, Joshua T.; Trevisan, Gabriele

    2016-08-01

    A thermally decoupled hidden sector of particles, with a mass gap, generically enters a phase of cannibalism in the early Universe. The Standard Model sector becomes exponentially colder than the hidden sector. We propose the cannibal dark matter framework, where dark matter resides in a cannibalizing sector with a relic density set by 2-to-2 annihilations. Observable signals of cannibal dark matter include a boosted rate for indirect detection, new relativistic degrees of freedom, and warm dark matter.

  8. The hidden universe

    SciTech Connect

    Disney, M.

    1985-01-01

    Astronomer Disney has followed a somewhat different tack than that of most popular books on cosmology by concentrating on the notion of hidden (as in not directly observable by its own radiation) matter in the universe.

  9. Hazing: Hidden Campus Crime.

    ERIC Educational Resources Information Center

    Hollmann, Barbara B.

    2002-01-01

    Initiation traditions and rites of passage are important for group and team membership, but the violent behavior and alcohol abuse involved in hazing constitute serious campus crime. This article helps campus administrators to develop new strategies for attacking the hidden crime of hazing. (Contains 32 references.) (Author)

  10. Probe into Gaseous Pollution and Assessment of Air Quality Benefit under Sector Dependent Emission Control Strategies over Megacities in Yangtze River Delta, China

    SciTech Connect

    Dong, Xinyi; Gao, Yang; Fu, Joshua S.; Li, Juan; Huang, Kan; Zhuang, G.; Zhou, Ying

    2013-11-01

    On February 29th 2012, China published its new National Ambient Air Quality Standard (CH-NAAQS) aiming at revising the standards and measurements for both gaseous pollutants including ozone (O3), nitrogen dioxide (NO2), and sulfur dioxide (SO2), and also particle pollutants including PM10 and PM2.5. In order to understand the air pollution status regarding this new standard, the integrated MM5/CMAQ modeling system was applied over Yangtze River Delta (YRD) within this study to examine the criteria gaseous pollutants listed in the new CH-NAAQS. Sensitivity simulations were also conducted to assess the responses of gaseous pollutants under 8 different sector-dependent emission reduction scenarios in order to evaluate the potential control strategies. 2006 was selected as the simulation year in order to review the air quality condition at the beginning of China’s 11th Five-Year-Plan (FYP, from 2006 to 2010), and also compared with air quality status in 2010 as the end of 11th FYP to probe into the effectiveness of the national emission control efforts. Base case simulation showed distinct seasonal variation for gaseous pollutants: SO2, and NO2 were found to have higher surface concentrations in winter while O3 was found to have higher concentrations in spring and summer than other seasons. According to the analyses focused on 3 megacities within YRD, Shanghai, Nanjing, and Hangzhou, we found different air quality conditions among the cities: NO2 was the primary pollutant that having the largest number of days exceeding the CH-NAAQS daily standard (80 μg/m3) in Shanghai (59 days) and Nanjing (27 days); SO2 was the primary pollutant with maximum number of days exceeding daily air quality standard (150 μg/m3) in Hangzhou (28 days), while O3 exceeding the daily maximum 8-hour standard (160 μg/m3) for relatively fewer days in all the three cities (9 days in Shanghai, 14 days in Nanjing, and 11 days in Hangzhou). Simulation results from predefined potential applicable

  11. Hidden attractors in dynamical systems

    NASA Astrophysics Data System (ADS)

    Dudkowski, Dawid; Jafari, Sajad; Kapitaniak, Tomasz; Kuznetsov, Nikolay V.; Leonov, Gennady A.; Prasad, Awadhesh

    2016-06-01

    Complex dynamical systems, ranging from the climate, ecosystems to financial markets and engineering applications typically have many coexisting attractors. This property of the system is called multistability. The final state, i.e., the attractor on which the multistable system evolves strongly depends on the initial conditions. Additionally, such systems are very sensitive towards noise and system parameters so a sudden shift to a contrasting regime may occur. To understand the dynamics of these systems one has to identify all possible attractors and their basins of attraction. Recently, it has been shown that multistability is connected with the occurrence of unpredictable attractors which have been called hidden attractors. The basins of attraction of the hidden attractors do not touch unstable fixed points (if exists) and are located far away from such points. Numerical localization of the hidden attractors is not straightforward since there are no transient processes leading to them from the neighborhoods of unstable fixed points and one has to use the special analytical-numerical procedures. From the viewpoint of applications, the identification of hidden attractors is the major issue. The knowledge about the emergence and properties of hidden attractors can increase the likelihood that the system will remain on the most desirable attractor and reduce the risk of the sudden jump to undesired behavior. We review the most representative examples of hidden attractors, discuss their theoretical properties and experimental observations. We also describe numerical methods which allow identification of the hidden attractors.

  12. A Hidden Twelve-Dimensional SuperPoincare Symmetry In Eleven Dimensions

    SciTech Connect

    Bars, Itzhak; Deliduman, Cemsinan; Pasqua, Andrea; Zumino, Bruno

    2003-12-13

    First, we review a result in our previous paper, of how a ten-dimensional superparticle, taken off-shell, has a hidden eleven-dimensional superPoincare symmetry. Then, we show that the physical sector is defined by three first-class constraints which preserve the full eleven-dimensional symmetry. Applying the same concepts to the eleven dimensional superparticle, taken off-shell, we discover a hidden twelve dimensional superPoincare symmetry that governs the theory.

  13. Quantum decoherence of photons in the presence of hidden U(1)s

    NASA Astrophysics Data System (ADS)

    Ahlers, M.; Anchordoqui, L. A.; Gonzalez-Garcia, M. C.

    2010-04-01

    Many extensions of the standard model predict the existence of hidden sectors that may contain unbroken Abelian gauge groups. We argue that in the presence of quantum decoherence photons may convert into hidden photons on sufficiently long time scales and show that this effect is strongly constrained by CMB and supernova data. In particular, Planck-scale suppressed decoherence scales D∝ω2/MPl (characteristic for noncritical string theories) are incompatible with the presence of even a single hidden U(1). The absence of photon decoherence in this simple standard model extension complements other strong bounds derived from solar, reactor, and atmospheric neutrinos.

  14. Quantum decoherence of photons in the presence of hidden U(1)s

    SciTech Connect

    Ahlers, M.; Anchordoqui, L. A.; Gonzalez-Garcia, M. C.

    2010-04-15

    Many extensions of the standard model predict the existence of hidden sectors that may contain unbroken Abelian gauge groups. We argue that in the presence of quantum decoherence photons may convert into hidden photons on sufficiently long time scales and show that this effect is strongly constrained by CMB and supernova data. In particular, Planck-scale suppressed decoherence scales D{proportional_to}{omega}{sup 2}/M{sub Pl} (characteristic for noncritical string theories) are incompatible with the presence of even a single hidden U(1). The absence of photon decoherence in this simple standard model extension complements other strong bounds derived from solar, reactor, and atmospheric neutrinos.

  15. Atlas of solar hidden photon emission

    NASA Astrophysics Data System (ADS)

    Redondo, Javier

    2015-07-01

    Hidden photons, gauge bosons of a U(1) symmetry of a hidden sector, can constitute the dark matter of the universe and a smoking gun for large volume compactifications of string theory. In the sub-eV mass range, a possible discovery experiment consists on searching the copious flux of these particles emitted from the Sun in a helioscope setup à la Sikivie. In this paper, we compute in great detail the flux of HPs from the Sun, a necessary ingredient for interpreting such experiments. We provide a detailed exposition of transverse photon-HP oscillations in inhomogenous media, with special focus on resonance oscillations, which play a leading role in many cases. The region of the Sun emitting HPs resonantly is a thin spherical shell for which we justify an averaged-emission formula and which implies a distinctive morphology of the angular distribution of HPs on Earth in many cases. Low mass HPs with energies in the visible and IR have resonances very close to the photosphere where the solar plasma is not fully ionised and requires building a detailed model of solar refraction and absorption. We present results for a broad range of HP masses (from 0-1 keV) and energies (from the IR to the X-ray range), the most complete atlas of solar HP emission to date.

  16. Atlas of solar hidden photon emission

    SciTech Connect

    Redondo, Javier

    2015-07-20

    Hidden photons, gauge bosons of a U(1) symmetry of a hidden sector, can constitute the dark matter of the universe and a smoking gun for large volume compactifications of string theory. In the sub-eV mass range, a possible discovery experiment consists on searching the copious flux of these particles emitted from the Sun in a helioscope setup à la Sikivie. In this paper, we compute in great detail the flux of HPs from the Sun, a necessary ingredient for interpreting such experiments. We provide a detailed exposition of transverse photon-HP oscillations in inhomogenous media, with special focus on resonance oscillations, which play a leading role in many cases. The region of the Sun emitting HPs resonantly is a thin spherical shell for which we justify an averaged-emission formula and which implies a distinctive morphology of the angular distribution of HPs on Earth in many cases. Low mass HPs with energies in the visible and IR have resonances very close to the photosphere where the solar plasma is not fully ionised and requires building a detailed model of solar refraction and absorption. We present results for a broad range of HP masses (from 0–1 keV) and energies (from the IR to the X-ray range), the most complete atlas of solar HP emission to date.

  17. Hidden Magnetic Portals Around Earth

    NASA Video Gallery

    A NASA-sponsored researcher at the University of Iowa has developed a way for spacecraft to hunt down hidden magnetic portals in the vicinity of Earth. These gateways link the magnetic field of our...

  18. Ethics, Equity, and Hidden Privilege.

    ERIC Educational Resources Information Center

    Lawler, Patricia A.

    1996-01-01

    Issues of race and gender are often overlooked in ethical dilemmas. Adult educators must be aware of core professional values, thoughtfully analyze their biases, and acknowledge hidden privileges. (JOW)

  19. Child Abuse: The Hidden Bruises

    MedlinePlus

    ... AACAP Facts for Families Guide Skip breadcrumb navigation Child Abuse - The Hidden Bruises Quick Links Facts For Families ... 5; Updated November 2014 The statistics on physical child abuse are alarming. It is estimated hundreds of thousands ...

  20. Hidden Statistics of Schroedinger Equation

    NASA Technical Reports Server (NTRS)

    Zak, Michail

    2011-01-01

    Work was carried out in determination of the mathematical origin of randomness in quantum mechanics and creating a hidden statistics of Schr dinger equation; i.e., to expose the transitional stochastic process as a "bridge" to the quantum world. The governing equations of hidden statistics would preserve such properties of quantum physics as superposition, entanglement, and direct-product decomposability while allowing one to measure its state variables using classical methods.

  1. Hidden asymmetry of ice.

    PubMed

    Kirov, Mikhail V

    2014-11-26

    Ice is a very complex and fundamentally important solid. In the present article, we review a new property of the hydrogen-bonded network in ice structures: an explicit nonequivalence of some antipodal configurations with the opposite direction of all hydrogen bonds (H-bonds). This asymmetry is most pronounced for the structures with considerable deviation of the H-bond network from the tetrahedral coordination. That is why we have investigated in detail four-coordinated ice nanostructures with no outer "dangling" hydrogen atoms, namely, ice bilayers and ice nanotubes consisting of stacked n-membered rings. The reason for this H-bonding asymmetry is a fundamental nonequivalence of the arrangements of water molecules in some antipodal configurations with the opposite direction of all H-bonds. For these configurations, the overall pictures of deviations of the hydrogen bonds from linearity are qualitatively different. We consider the reversal of all H-bonds as an additional nongeometric operation of symmetry, more precisely antisymmetry. It is not easy to find the explicit breaking of the symmetry of hydrogen bonding (H-symmetry) in the variety of all configurations. Therefore, this asymmetry may be named hidden. PMID:24905908

  2. Hidden symmetries and black holes

    NASA Astrophysics Data System (ADS)

    Frolov, Valeri P.

    2009-10-01

    The paper contains a brief review of recent results on hidden symmetries in higher dimensional black hole spacetimes. We show how the existence of a principal CKY tensor (that is a closed conformal Killing-Yano 2-form) allows one to generate a `tower' of Killing-Yano and Killing tensors responsible for hidden symmetries. These symmetries imply complete integrability of geodesic equations and the complete separation of variables in the Hamilton-Jacobi, Klein-Gordon, Dirac and gravitational perturbation equations in the general Kerr-NUT-(A)dS metrics. Equations of the parallel transport of frames along geodesics in these spacetimes are also integrable.

  3. Hidden symmetries in jammed systems

    NASA Astrophysics Data System (ADS)

    Morse, Peter K.; Corwin, Eric I.

    2016-07-01

    There are deep, but hidden, geometric structures within jammed systems, associated with hidden symmetries. These can be revealed by repeated transformations under which these structures lead to fixed points. These geometric structures can be found in the Voronoi tesselation of space defined by the packing. In this paper we examine two iterative processes: maximum inscribed sphere (MIS) inversion and a real-space coarsening scheme. Under repeated iterations of the MIS inversion process we find invariant systems in which every particle is equal to the maximum inscribed sphere within its Voronoi cell. Using a real-space coarsening scheme we reveal behavior in geometric order parameters which is length-scale invariant.

  4. Phenomenology of pure-gauge hidden valleys at hadron colliders

    NASA Astrophysics Data System (ADS)

    Juknevich, Jose E.

    Expectations for new physics at the LHC have been greatly influenced by the Hierarchy problem of electroweak symmetry breaking. However, there are reasons to believe that the LHC may still discover new physics, but not directly related to the resolution of the Hierarchy problem. To ensure that such a physics does not go undiscovered requires precise understanding of how new phenomena will reveal themselves in the current and future generation of particle-physics experiments. Given this fact it seems sensible to explore other approaches to this problem; we study three alternatives here. In this thesis I argue for the plausibility that the standard model is coupled, through new massive charged or colored particles, to a hidden sector whose low energy dynamics is controlled by a pure Yang-Mills theory, with no light matter. Such a sector would have numerous metastable "hidden glueballs" built from the hidden gluons. These states would decay to particles of the standard model. I consider the phenomenology of this scenario, and find formulas for the lifetimes and branching ratios of the most important of these states. The dominant decays are to two standard model gauge bosons or to fermion-antifermion pairs, or by radiative decays with photon or Higgs emission, leading to jet- and photon-rich signals, and some occasional leptons. The presence of effective operators of different mass dimensions, often competing with each other, together with a great diversity of states, leads to a great variability in the lifetimes and decay modes of the hidden glueballs. I find that most of the operators considered in this work are not heavily constrained by precision electroweak physics, therefore leaving plenty of room in the parameter space to be explored by the future experiments at the LHC. Finally, I discuss several issues on the phenomenology of the new massive particles as well as an outlook for experimental searches.

  5. Hidden order in spin-liquid Gd₃Ga₅O₁₂.

    PubMed

    Paddison, Joseph A M; Jacobsen, Henrik; Petrenko, Oleg A; Fernández-Díaz, Maria Teresa; Deen, Pascale P; Goodwin, Andrew L

    2015-10-01

    Frustrated magnetic materials are promising candidates for new states of matter because lattice geometry suppresses conventional magnetic dipole order, potentially allowing "hidden" order to emerge in its place. A model of a hidden-order state at the atomic scale is difficult to deduce because microscopic probes are not directly sensitive to hidden order. Here, we develop such a model of the spin-liquid state in the canonical frustrated magnet gadolinium gallium garnet (Gd3Ga5O12). We show that this state exhibits a long-range hidden order in which multipoles are formed from 10-spin loops. The order is a consequence of the interplay between antiferromagnetic spin correlations and local magnetic anisotropy, which allows it to be indirectly observed in neutron-scattering experiments. PMID:26450205

  6. The Hidden Dimensions of Databases.

    ERIC Educational Resources Information Center

    Jacso, Peter

    1994-01-01

    Discusses methods of evaluating commercial online databases and provides examples that illustrate their hidden dimensions. Topics addressed include size, including the number of records or the number of titles; the number of years covered; and the frequency of updates. Comparisons of Readers' Guide Abstracts and Magazine Article Summaries are…

  7. Hidden Costs of School Construction.

    ERIC Educational Resources Information Center

    Glass, Thomas E.

    1999-01-01

    Costs that may increase the original school construction estimates include school-design inefficiency, architect fees, and costs for land, site development, technology, demolition, consultants, and security. A quality-review team can plan to avoid hidden costs and ensure that the new facility will meet instructional needs at the least possible…

  8. Preschoolers Search for Hidden Objects

    ERIC Educational Resources Information Center

    Haddad, Jeffrey M.; Chen, Yuping; Keen, Rachel

    2011-01-01

    The issue of whether young children use spatio-temporal information (e.g., movement of objects through time and space) and/or contact-mechanical information (e.g., interaction between objects) to search for a hidden object was investigated. To determine whether one cue can have priority over the other, a dynamic event that put these cues into…

  9. Sexual Harrassment: A Hidden Problem.

    ERIC Educational Resources Information Center

    Sandler, Bernice R.; And Others

    1981-01-01

    The hidden but serious problem of sexual harassment of students and employees by college faculty is discussed, some statistics are given, and legal and court opinions outlined. Harassment as a violation of Title IX is analyzed, and implications for institutional action to curb it are outlined. (MSE)

  10. Electronic hidden solder joint geometry characterization

    NASA Astrophysics Data System (ADS)

    Hsieh, Sheng-Jen

    2009-05-01

    To reduce the size of electronic equipment, multi-layer printed circuit board structures have become popular in recent years. As a result, the inspection of hidden solder joints between layers of boards has become increasingly difficult. Xray machines have been used for ball grid array (BGA) and hidden solder joint inspection; however, the equipment is costly and the inspection process is time consuming. In this paper, we investigate an active thermography approach to probing solder joint geometry. A set of boards having the same number of solder joints and amount of solder paste (0.061 g) was fabricated. Each solder joint had a different geometry. A semi-automated system was built to heat and then transfer each board to a chamber where an infrared camera was used to scan the board as it was cooling down. Two-thirds of the data set was used for model development and one-third was used for model evaluation. Both artificial neural network (ANN) and binary logistic regression models were constructed. Results suggest that solder joints with more surface area cool much faster than those with less surface area. In addition, both modeling approaches are consistent in predicting solder geometry; ANN had 85% accuracy and the regression model had 80%. This approach can potentially be used to test for cold solder joints prior to BGA assembly, since cold solder joints may have air gaps between the joint and the board and air is a poor heat conductor. Therefore, a cold solder joint may have a slower cooling rate than a normal one.

  11. The hidden dragons.

    PubMed

    Zeng, Ming; Williamson, Peter J

    2003-10-01

    Most multinational corporations are fascinated with China. Carried away by the number of potential customers and the relatively cheap labor, firms seeking a presence in China have traditionally focused on selling products, setting up manufacturing facilities, or both. But they've ignored an important development: the emergence of Chinese firms as powerful rivals--in China and also in the global market. In this article, Ming Zeng and Peter Williamson describe how Chinese companies like Haier, Legend, and Pearl River Piano have quietly managed to grab market share from older, bigger, and financially stronger rivals in Asia, Europe, and the United States. Global managers tend to offer the usual explanations for why Chinese companies don't pose a threat: They aren't big enough or profitable enough to compete overseas, the managers say, and these primarily state-owned companies are ill-financed and ill-equipped for global competition. As the government's policies about the private ownership of companies changed from forbidding the practice to encouraging it, a new breed of Chinese companies evolved. The authors outline the four types of hybrid Chinese companies that are simultaneously tackling the global market. China's national champions are using their advantages as domestic leaders to build global brands. The dedicated exporters are entering foreign markets on the strength of their economies of scale. The competitive networks have taken on world markets by bringing together small, specialized companies that operate in close proximity. And the technology upstarts are using innovations developed by China's government-owned research institutes to enter emerging sectors such as biotechnology. Zeng and Williamson identify these budding multinationals, analyze their strategies, and evaluate their weaknesses. PMID:14521101

  12. Rotating concave eddy current probe

    DOEpatents

    Roach, Dennis P.; Walkington, Phil; Rackow, Kirk A.; Hohman, Ed

    2008-04-01

    A rotating concave eddy current probe for detecting fatigue cracks hidden from view underneath the head of a raised head fastener, such as a buttonhead-type rivet, used to join together structural skins, such as aluminum aircraft skins. The probe has a recessed concave dimple in its bottom surface that closely conforms to the shape of the raised head. The concave dimple holds the probe in good alignment on top of the rivet while the probe is rotated around the rivet's centerline. One or more magnetic coils are rigidly embedded within the probe's cylindrical body, which is made of a non-conducting material. This design overcomes the inspection impediment associated with widely varying conductivity in fastened joints.

  13. Mystery of the Hidden Cosmos [Complex Dark Matter

    SciTech Connect

    Dobrescu, Bogdan A.; Lincoln, Don

    2015-06-16

    Scientists know there must be more matter in the universe than what is visible. Searches for this dark matter have focused on a single unseen particle, but decades of experiments have been unsuccessful at finding it. Exotic possibilities for dark matter are looking increasingly plausible. Rather than just one particle, dark matter could contain an entire world of particles and forces that barely interact with normal matter. Complex dark matter could form dark atoms and molecules and even clump together to make hidden galactic disks that overlap with the spiral arms of the Milky Way and other galaxies. Experiments are under way to search for evidence of such a dark sector.

  14. Diffusion of hidden charm mesons in hadronic medium

    NASA Astrophysics Data System (ADS)

    Mitra, Sukanya; Ghosh, Sabyasachi; Das, Santosh K.; Sarkar, Sourav; Alam, Jan-e.

    2016-07-01

    The drag and diffusion coefficients of a hot hadronic medium have been evaluated by using hidden charm mesons as probes. The scattering amplitudes required for the evaluation of these coefficients are calculated using an effective theory and scattering lengths obtained from lattice QCD calculations. It is found that although the magnitude of the transport coefficients are small their temperature variation is strong. The insignificant momentum diffusion of J / ψ in the hadronic medium keeps their momentum distribution largely unaltered. Therefore, the task of characterization of quark gluon plasma by using the observed suppression of J / ψ at high momentum will be comparatively easier.

  15. Probe assembly

    SciTech Connect

    Avera, C.J.

    1981-01-06

    A hand-held probe assembly, suitable for monitoring a radioactive fibrinogen tracer, is disclosed comprising a substantially cylindrically shaped probe handle having an open end. The probe handle is adapted to be interconnected with electrical circuitry for monitoring radioactivity that is sensed or detected by the probe assembly. Mounted within the probe handle is a probe body assembly that includes a cylindrically shaped probe body inserted through the open end of the probe handle. The probe body includes a photomultiplier tube that is electrically connected with a male connector positioned at the rearward end of the probe body. Mounted at the opposite end of the probe body is a probe head which supports an optical coupler therewithin. The probe head is interconnected with a probe cap which supports a detecting crystal. The probe body assembly, which consists of the probe body, the probe head, and the probe cap is supported within the probe handle by means of a pair of compressible o-rings which permit the probe assembly to be freely rotatable, preferably through 360*, within the probe handle and removable therefrom without requiring any disassembly.

  16. Decaying hidden dark matter in warped compactification

    SciTech Connect

    Chen, Xingang

    2009-09-01

    The recent PAMELA and ATIC/Fermi/HESS experiments have observed an excess of electrons and positrons, but not anti-protons, in the high energy cosmic rays. To explain this result, we construct a decaying hidden dark matter model in string theory compactification that incorporates the following two ingredients, the hidden dark matter scenario in warped compactification and the phenomenological proposal of hidden light particles that decay to the Standard Model. In this model, on higher dimensional warped branes, various warped Kaluza-Klein particles and the zero-mode of gauge field play roles of the hidden dark matter or mediators to the Standard Model.

  17. Quantum computation and hidden variables

    NASA Astrophysics Data System (ADS)

    Aristov, V. V.; Nikulov, A. V.

    2008-03-01

    Many physicists limit oneself to an instrumentalist description of quantum phenomena and ignore the problems of foundation and interpretation of quantum mechanics. This instrumentalist approach results to "specialization barbarism" and mass delusion concerning the problem, how a quantum computer can be made. The idea of quantum computation can be described within the limits of quantum formalism. But in order to understand how this idea can be put into practice one should realize the question: "What could the quantum formalism describe?", in spite of the absence of an universally recognized answer. Only a realization of this question and the undecided problem of quantum foundations allows to see in which quantum systems the superposition and EPR correlation could be expected. Because of the "specialization barbarism" many authors are sure that Bell proved full impossibility of any hidden-variables interpretation. Therefore it is important to emphasize that in reality Bell has restricted to validity limits of the no-hidden-variables proof and has shown that two-state quantum system can be described by hidden variables. The later means that no experimental result obtained on two-state quantum system can prove the existence of superposition and violation of the realism. One should not assume before unambiguous experimental evidence that any two-state quantum system is quantum bit. No experimental evidence of superposition of macroscopically distinct quantum states and of a quantum bit on base of superconductor structure was obtained for the present. Moreover same experimental results can not be described in the limits of the quantum formalism.

  18. Hidden variables: the resonance factor

    NASA Astrophysics Data System (ADS)

    Brooks, Juliana H. J.

    2009-08-01

    In 1900 Max Karl Planck performed his famous black-body radiation work which sparked the quantum revolution. Re-examination of that work has revealed hidden variables, consistent with Einstein's famous sentiment that quantum mechanics is incomplete due to the existence of "hidden variables". The recent discovery of these previously hidden variables, which have been missing from foundational equations for more than one hundred years, has important implications for theoretical, experimental and applied sciences and technologies. Planck attempted to integrate the new "resonant Hertzian (electromagnetic) waves", with existing Helmholtz theories on energy and thermodynamics. In his famous January 1901, paper on black-body radiation, Planck described two significant hypotheses - his well known Quantum Hypothesis, and his more obscure Resonance Hypothesis. Few scientists today are aware that Planck hypothesized resonant electromagnetic energy as a form of non-thermal energy available to perform work on a molecular basis, and that Planck's Resonance Hypothesis bridged the gap between classical Helmholtz energy state dynamics of the bulk macrostate, and energy state dynamics of the molecular microstate. Since the black-body experimental data involved only a thermal effect and not a resonant effect, Planck excluded the resonant state in his black-body derivation. He calculated Boltzmann's constant "kB" using completely thermal/entropic data, arriving at a value of 1.38 ×10-23 J K-1 per molecule, representing the internal energy of a molecule under completely thermal conditions. He further hypothesized, however, that if resonant energy was present in a system, the resonant energy would be "free to be converted into work". Planck seems to have been caught up in the events of the quantum revolution and never returned to his Resonance Hypothesis. As a result, a mathematical foundation for resonance dynamics was never completed. Boltzmann's constant was adopted into

  19. Random graphs with hidden color.

    PubMed

    Söderberg, Bo

    2003-07-01

    We propose and investigate a unifying class of sparse random graph models, based on a hidden coloring of edge-vertex incidences, extending an existing approach, random graphs with a given degree distribution, in a way that admits a nontrivial correlation structure in the resulting graphs. The approach unifies a number of existing random graph ensembles within a common general formalism, and allows for the analytic calculation of observable graph characteristics. In particular, generating function techniques are used to derive the size distribution of connected components (clusters) as well as the location of the percolation threshold where a giant component appears. PMID:12935185

  20. Unpolarized states and hidden polarization

    NASA Astrophysics Data System (ADS)

    de la Hoz, P.; Björk, G.; Klimov, A. B.; Leuchs, G.; Sánchez-Soto, L. L.

    2014-10-01

    We capitalize on a multipolar expansion of the polarization density matrix, in which multipoles appear as successive moments of the Stokes variables. When all the multipoles up to a given order K vanish, we can properly say that the state is Kth-order unpolarized, as it lacks of polarization information to that order. First-order unpolarized states coincide with the corresponding classical ones, whereas unpolarized to any order tally with the quantum notion of fully invariant states. In between these two extreme cases, there is a rich variety of situations that are explored here. The existence of hidden polarization emerges in a natural way in this context.

  1. Dissolved gas - the hidden saboteur

    SciTech Connect

    Magorien, V.G.

    1993-12-31

    Almost all hydraulic power components, to properly perform their tasks, rely on one basic, physical property, i.e., the incompressibility of the working fluid. Unfortunately, a frequently overlooked fluid property which frustrates this requirement is its ability to absorb, i.e., dissolve, store and give off gas. The gas is, most often but not always, air. This property is a complex one because it is a function not only of the fluid`s chemical make-up but temperature, pressure, exposed area, depth and time. In its relationshiop to aircraft landing-gear, where energy is absorbed hydraulically, this multi-faceted fluid property can be detrimental in two ways: dynamically, i.e., loss of energy absorption ability and statically, i.e., improper aircraft attitude on the ground. The pupose of this paper is to bring an awareness to this property by presenting: (1) examples of these manifestations with some empirical and practical solutions to them, (2) illustrations of this normally `hidden saboteur` at work, (3) Henry`s Dissolved Gas Law, (4) room-temperature, saturated values of dissolved gas for a number of different working fluids, (5) a description of the instrument used to obtain them, (6) some `missing elements` of the Dissolved Gas Law pertaining to absoption, (7) how static and dynamic conditions effect gas absorption and (8) some recommended solutions to prevent becoming a victim of this `hidden saboteur`

  2. Hidden scale invariance of metals

    NASA Astrophysics Data System (ADS)

    Hummel, Felix; Kresse, Georg; Dyre, Jeppe C.; Pedersen, Ulf R.

    2015-11-01

    Density functional theory (DFT) calculations of 58 liquid elements at their triple point show that most metals exhibit near proportionality between the thermal fluctuations of the virial and the potential energy in the isochoric ensemble. This demonstrates a general "hidden" scale invariance of metals making the condensed part of the thermodynamic phase diagram effectively one dimensional with respect to structure and dynamics. DFT computed density scaling exponents, related to the Grüneisen parameter, are in good agreement with experimental values for the 16 elements where reliable data were available. Hidden scale invariance is demonstrated in detail for magnesium by showing invariance of structure and dynamics. Computed melting curves of period three metals follow curves with invariance (isomorphs). The experimental structure factor of magnesium is predicted by assuming scale invariant inverse power-law (IPL) pair interactions. However, crystal packings of several transition metals (V, Cr, Mn, Fe, Nb, Mo, Ta, W, and Hg), most post-transition metals (Ga, In, Sn, and Tl), and the metalloids Si and Ge cannot be explained by the IPL assumption. The virial-energy correlation coefficients of iron and phosphorous are shown to increase at elevated pressures. Finally, we discuss how scale invariance explains the Grüneisen equation of state and a number of well-known empirical melting and freezing rules.

  3. Beyond Curriculum Reform: Confronting Medicine's Hidden Curriculum.

    ERIC Educational Resources Information Center

    Hafferty, Frederic W.

    1998-01-01

    Discusses the existence of three curricula in medical schools (formal, informal, and hidden) and suggests that educators and administrators investigate the hidden curriculum by examining four areas: institutional policies; evaluation practices; resource-allocation decisions; and institutional "slang." Needed reforms in accreditation standards are…

  4. Hidden Curriculum in Continuing Medical Education

    ERIC Educational Resources Information Center

    Bennett, Nancy; Lockyer, Jocelyn; Mann, Karen; Batty, Helen; LaForet, Karen; Rethans, Jan-Joost; Silver, Ivan

    2004-01-01

    In developing curricula for undergraduate and graduate medical education, educators have become increasingly aware of an interweaving of the formal, informal, and hidden curricula and their influences on the outcomes of teaching and learning. But, to date, there is little in the literature about the hidden curriculum of medical practice, which…

  5. Hidden Variable Theories and Quantum Nonlocality

    ERIC Educational Resources Information Center

    Boozer, A. D.

    2009-01-01

    We clarify the meaning of Bell's theorem and its implications for the construction of hidden variable theories by considering an example system consisting of two entangled spin-1/2 particles. Using this example, we present a simplified version of Bell's theorem and describe several hidden variable theories that agree with the predictions of…

  6. Building Simple Hidden Markov Models. Classroom Notes

    ERIC Educational Resources Information Center

    Ching, Wai-Ki; Ng, Michael K.

    2004-01-01

    Hidden Markov models (HMMs) are widely used in bioinformatics, speech recognition and many other areas. This note presents HMMs via the framework of classical Markov chain models. A simple example is given to illustrate the model. An estimation method for the transition probabilities of the hidden states is also discussed.

  7. Heating up the Galaxy with hidden photons

    SciTech Connect

    Dubovsky, Sergei; Hernández-Chifflet, Guzmán

    2015-12-29

    We elaborate on the dynamics of ionized interstellar medium in the presence of hidden photon dark matter. Our main focus is the ultra-light regime, where the hidden photon mass is smaller than the plasma frequency in the Milky Way. We point out that as a result of the Galactic plasma shielding direct detection of ultra-light photons in this mass range is especially challenging. However, we demonstrate that ultra-light hidden photon dark matter provides a powerful heating source for the ionized interstellar medium. This results in a strong bound on the kinetic mixing between hidden and regular photons all the way down to the hidden photon masses of order 10{sup −20} eV.

  8. Stochastic thermodynamics of hidden pumps

    NASA Astrophysics Data System (ADS)

    Esposito, Massimiliano; Parrondo, Juan M. R.

    2015-05-01

    We show that a reversible pumping mechanism operating between two states of a kinetic network can give rise to Poisson transitions between these two states. An external observer, for whom the pumping mechanism is not accessible, will observe a Markov chain satisfying local detailed balance with an emerging effective force induced by the hidden pump. Due to the reversibility of the pump, the actual entropy production turns out to be lower than the coarse-grained entropy production estimated from the flows and affinities of the resulting Markov chain. Moreover, in presence of a large time scale separation between the fast-pumping dynamics and the slow-network dynamics, a finite current with zero dissipation may be produced. We make use of these general results to build a synthetase-like kinetic scheme able to reversibly produce high free-energy molecules at a finite rate and a rotatory motor achieving 100% efficiency at finite speed.

  9. Stochastic thermodynamics of hidden pumps.

    PubMed

    Esposito, Massimiliano; Parrondo, Juan M R

    2015-05-01

    We show that a reversible pumping mechanism operating between two states of a kinetic network can give rise to Poisson transitions between these two states. An external observer, for whom the pumping mechanism is not accessible, will observe a Markov chain satisfying local detailed balance with an emerging effective force induced by the hidden pump. Due to the reversibility of the pump, the actual entropy production turns out to be lower than the coarse-grained entropy production estimated from the flows and affinities of the resulting Markov chain. Moreover, in presence of a large time scale separation between the fast-pumping dynamics and the slow-network dynamics, a finite current with zero dissipation may be produced. We make use of these general results to build a synthetase-like kinetic scheme able to reversibly produce high free-energy molecules at a finite rate and a rotatory motor achieving 100% efficiency at finite speed. PMID:26066126

  10. Variational Infinite Hidden Conditional Random Fields.

    PubMed

    Bousmalis, Konstantinos; Zafeiriou, Stefanos; Morency, Louis-Philippe; Pantic, Maja; Ghahramani, Zoubin

    2015-09-01

    Hidden conditional random fields (HCRFs) are discriminative latent variable models which have been shown to successfully learn the hidden structure of a given classification problem. An Infinite hidden conditional random field is a hidden conditional random field with a countably infinite number of hidden states, which rids us not only of the necessity to specify a priori a fixed number of hidden states available but also of the problem of overfitting. Markov chain Monte Carlo (MCMC) sampling algorithms are often employed for inference in such models. However, convergence of such algorithms is rather difficult to verify, and as the complexity of the task at hand increases the computational cost of such algorithms often becomes prohibitive. These limitations can be overcome by variational techniques. In this paper, we present a generalized framework for infinite HCRF models, and a novel variational inference approach on a model based on coupled Dirichlet Process Mixtures, the HCRF-DPM. We show that the variational HCRF-DPM is able to converge to a correct number of represented hidden states, and performs as well as the best parametric HCRFs-chosen via cross-validation-for the difficult tasks of recognizing instances of agreement, disagreement, and pain in audiovisual sequences. PMID:26353136

  11. Finding an apprenticeship: hidden curriculum and social consequences.

    PubMed

    Goastellec, Gaële; Ruiz, Guillaume

    2015-01-01

    In Switzerland, the majority of students are oriented toward professional training after compulsory schooling. At this stage, one of the biggest challenges for them is to find an apprenticeship position. Matching supply and demand is a complex process that not only excludes some students from having direct access to professional training but also forces them to make early choices regarding their future sector of employment. So, how does one find an apprenticeship? And what do the students' descriptions of their search for apprenticeships reveal about the institutional determinants of social inequalities at play in the system? Based on 29 interviews conducted in 2014 with 23 apprentices and 6 recruiters in the Canton of Vaud, this article interrogates how the dimensions of educational and social trajectories combine to affect access to apprenticeships and are accentuated by recruiters using a "hidden curriculum" during the recruitment process. A hidden curriculum consists of knowledge and skills not taught by the educational institution but which appear decisive in obtaining an apprenticeship. By analyzing the contrasting experiences of students in their search for an apprenticeship, we identify four types of trajectories that explain different types of school-to-apprenticeship transitions. We show how these determinants are reinforced by the "hidden curriculum" of recruitment based on the soft skills of feeling, autonomy, anticipation, and reflexivity that are assessed in the context of recruitment interactions. The discussion section debates how the criteria that appear to be used to identify the "right apprentice" tend to (re)produce inequalities between students. This not only depends on their academic results but also on their social and cultural skills, their ability to anticipate their choices and, more widely, their ability to be a subject in their recruitment search. "The Subject is neither the individual, nor the self, but the work through which an

  12. Results from the Solar Hidden Photon Search (SHIPS)

    SciTech Connect

    Schwarz, Matthias; Knabbe, Ernst-Axel; Lindner, Axel; Redondo, Javier; Ringwald, Andreas; Schneide, Magnus; Susol, Jaroslaw; Wiedemann, Günter

    2015-08-07

    We present the results of a search for transversely polarised hidden photons (HPs) with ∼3 eV energies emitted from the Sun. These hypothetical particles, known also as paraphotons or dark sector photons, are theoretically well motivated for example by string theory inspired extensions of the Standard Model. Solar HPs of sub-eV mass can convert into photons of the same energy (photon ↔ HP oscillations are similar to neutrino flavour oscillations). At SHIPS this would take place inside a long light-tight high-vacuum tube, which tracks the Sun. The generated photons would then be focused into a low-noise photomultiplier at the far end of the tube. Our analysis of 330 h of data (and 330 h of background characterisation) reveals no signal of photons from solar hidden photon conversion. We estimate the rate of newly generated photons due to this conversion to be smaller than 25 mHz/m{sup 2} at the 95% C.L. Using this and a recent model of solar HP emission, we set stringent constraints on χ, the coupling constant between HPs and photons, as a function of the HP mass.

  13. Results from the Solar Hidden Photon Search (SHIPS)

    NASA Astrophysics Data System (ADS)

    Schwarz, Matthias; Knabbe, Ernst-Axel; Lindner, Axel; Redondo, Javier; Ringwald, Andreas; Schneide, Magnus; Susol, Jaroslaw; Wiedemann, Günter

    2015-08-01

    We present the results of a search for transversely polarised hidden photons (HPs) with ~ 3 eV energies emitted from the Sun. These hypothetical particles, known also as paraphotons or dark sector photons, are theoretically well motivated for example by string theory inspired extensions of the Standard Model. Solar HPs of sub-eV mass can convert into photons of the same energy (photon leftrightarrow HP oscillations are similar to neutrino flavour oscillations). At SHIPS this would take place inside a long light-tight high-vacuum tube, which tracks the Sun. The generated photons would then be focused into a low-noise photomultiplier at the far end of the tube. Our analysis of 330 h of data (and 330 h of background characterisation) reveals no signal of photons from solar hidden photon conversion. We estimate the rate of newly generated photons due to this conversion to be smaller than 25 mHz/m2 at the 95% C.L . Using this and a recent model of solar HP emission, we set stringent constraints on χ, the coupling constant between HPs and photons, as a function of the HP mass.

  14. Fibroid Tumors in Women: A Hidden Epidemic?

    MedlinePlus

    Skip Navigation Bar Home Current Issue Past Issues Fibroid Tumors in Women: A Hidden Epidemic? Past Issues / ... risk for a woman to develop tumors." Got Fibroids? Volunteers Wanted: Sisters Who Have (Or Have Had) ...

  15. Perspective: Disclosing hidden sources of funding.

    PubMed

    Resnik, David B

    2009-09-01

    In this article, the author discusses ethical and policy issues related to the disclosure of hidden sources of funding in research. The author argues that authors have an ethical obligation to disclose hidden sources of funding and that journals should adopt policies to enforce this obligation. Journal policies should require disclosure of hidden sources of funding that authors know about and that have a direct relation to their research. To stimulate this discussion, the author describes a recent case: investigators who conducted a lung cancer screening study had received funding from a private foundation that was supported by a tobacco company, but they did not disclose this relationship to the journal. Investigators and journal editors must be prepared to deal with these issues in a manner that promotes honesty, transparency, fairness, and accountability in research. The development of well-defined, reasonable policies pertaining to hidden sources of funding can be a step in this direction. PMID:19707061

  16. Mystery of the Hidden Cosmos [Complex Dark Matter

    DOE PAGESBeta

    Dobrescu, Bogdan A.; Lincoln, Don

    2015-06-16

    Scientists know there must be more matter in the universe than what is visible. Searches for this dark matter have focused on a single unseen particle, but decades of experiments have been unsuccessful at finding it. Exotic possibilities for dark matter are looking increasingly plausible. Rather than just one particle, dark matter could contain an entire world of particles and forces that barely interact with normal matter. Complex dark matter could form dark atoms and molecules and even clump together to make hidden galactic disks that overlap with the spiral arms of the Milky Way and other galaxies. Experiments aremore » under way to search for evidence of such a dark sector.« less

  17. An acoustic microscopy technique reveals hidden morphological defenses in Daphnia.

    PubMed

    Laforsch, Christian; Ngwa, Wilfred; Grill, Wolfgang; Tollrian, Ralph

    2004-11-01

    Inducible defenses are common strategies for coping with the selective force of predation in heterogeneous environments. In recent years the conspicuous and often dramatic morphological plasticity of several waterflea species of the genus Daphnia have been found to be inducible defenses activated by chemical cues released by predators. However, the exact defensive mechanisms remained mysterious. Because even some minute morphological alterations proved to be protective against predatory invertebrates, it has been suggested that the visible morphological changes are only the tip of the iceberg of the entire protective mechanisms. Here we applied a method of ultrasonic microscopy with vector contrast at 1.2 GHz to probe hidden morphological defenses. We found that induction with predator kairomones increases the stability of the carapace in two Daphnia species up to 350%. This morphological plasticity provides a major advantage for the induced morphs during predation because predatory invertebrates need to crush or puncture the carapace of their prey to consume them. Our ultrastructural analyses revealed that the internal architecture of the carapace ensures maximal rigidity with minimal material investment. Our results uncover hidden morphological plasticity and suggest a reconsideration of former classification systems in defended and undefended genotypes in Daphnia and possibly in other prey organisms as well. PMID:15520396

  18. Spectrophotometric probe

    DOEpatents

    Prather, W.S.; O'Rourke, P.E.

    1994-08-02

    A support structure is described bearing at least one probe for making spectrophotometric measurements of a fluid using a source of light and a spectrophotometer. The probe includes a housing with two optical fibers and a planoconvex lens. A sleeve bearing a mirror surrounds the housing. The lens is separated from the mirror by a fixed distance, defining an interior space for receiving a volume of the fluid sample. A plurality of throughholes extending through the sleeve communicate between the sample volume and the exterior of the probe, all but one hole bearing a screen. A protective jacket surrounds the probe. A hollow conduit bearing a tube is formed in the wall of the probe for venting any air in the interior space when fluid enters. The probe is held at an acute angle so the optic fibers carrying the light to and from the probe are not bent severely on emergence from the probe. 3 figs.

  19. Spectrophotometric probe

    DOEpatents

    Prather, William S.; O'Rourke, Patrick E.

    1994-01-01

    A support structure bearing at least one probe for making spectrophotometric measurements of a fluid using a source of light and a spectrophotometer. The probe includes a housing with two optical fibers and a planoconvex lens. A sleeve bearing a mirror surrounds the housing. The lens is separated from the mirror by a fixed distance, defining an interior space for receiving a volume of the fluid sample. A plurality of throughholes extending through the sleeve communicate between the sample volume and the exterior of the probe, all but one hole bearing a screen. A protective jacket surrounds the probe. A hollow conduit bearing a tube is formed in the wall of the probe for venting any air in the interior space when fluid enters. The probe is held at an acute angle so the optic fibers carrying the light to and from the probe are not bent severely on emergence from the probe.

  20. New hidden beauty molecules predicted by the local hidden gauge approach and heavy quark spin symmetry

    NASA Astrophysics Data System (ADS)

    Xiao, C. W.; Ozpineci, A.; Oset, E.

    2015-10-01

    Using a coupled channel unitary approach, combining the heavy quark spin symmetry and the dynamics of the local hidden gauge, we investigate the meson-meson interaction with hidden beauty. We obtain several new states of isospin I = 0: six bound states, and weakly bound six more possible states which depend on the influence of the coupled channel effects.

  1. Detecting targets hidden in random forests

    NASA Astrophysics Data System (ADS)

    Kouritzin, Michael A.; Luo, Dandan; Newton, Fraser; Wu, Biao

    2009-05-01

    Military tanks, cargo or troop carriers, missile carriers or rocket launchers often hide themselves from detection in the forests. This plagues the detection problem of locating these hidden targets. An electro-optic camera mounted on a surveillance aircraft or unmanned aerial vehicle is used to capture the images of the forests with possible hidden targets, e.g., rocket launchers. We consider random forests of longitudinal and latitudinal correlations. Specifically, foliage coverage is encoded with a binary representation (i.e., foliage or no foliage), and is correlated in adjacent regions. We address the detection problem of camouflaged targets hidden in random forests by building memory into the observations. In particular, we propose an efficient algorithm to generate random forests, ground, and camouflage of hidden targets with two dimensional correlations. The observations are a sequence of snapshots consisting of foliage-obscured ground or target. Theoretically, detection is possible because there are subtle differences in the correlations of the ground and camouflage of the rocket launcher. However, these differences are well beyond human perception. To detect the presence of hidden targets automatically, we develop a Markov representation for these sequences and modify the classical filtering equations to allow the Markov chain observation. Particle filters are used to estimate the position of the targets in combination with a novel random weighting technique. Furthermore, we give positive proof-of-concept simulations.

  2. Dark radiation constraints on minicharged particles in models with a hidden photon

    SciTech Connect

    Vogel, Hendrik; Redondo, Javier E-mail: redondo@mpp.mpg.de

    2014-02-01

    We compute the thermalization of a hidden sector consisting of minicharged fermions (MCPs) and massless hidden photons in the early Universe. The precise measurement of the anisotropies of the cosmic microwave background (CMB) by Planck and the relic abundance of light nuclei produced during big bang nucleosynthesis (BBN) constrain the amount of dark radiation of this hidden sector through the effective number of neutrino species, N{sub eff}. This study presents novel and accurate predictions of dark radiation in the strongly and weakly coupled regime for a wide range of model parameters. We give the value of N{sub eff} for MCP masses between ∼ 100 keV and 10 GeV and minicharges in the range 10{sup −11}−1. Our results can be used to constrain MCPs with the current data and they are also a valuable indicator for future experimental searches, should the hint for dark radiation manifest itself in the next release of Planck's data.

  3. Central Compact Objects in Kes 79 and RCW 103 as `Hidden' Magnetars with Crustal Activity

    NASA Astrophysics Data System (ADS)

    Popov, S. B.; Kaurov, A. A.; Kaminker, A. D.

    2015-05-01

    We propose that observations of `hidden' magnetars in central compact objects can be used to probe crustal activity of neutron stars with large internal magnetic fields. Estimates based on calculations by Perna & Pons, Pons & Rea and Kaminker et al. suggest that central compact objects, which are proposed to be `hidden' magnetars, must demonstrate flux variations on the time scale of months-years. However, the most prominent candidate for the `hidden' magnetars - CXO J1852.6+0040 in Kes 79 - shows constant (within error bars) flux. This can be interpreted by lower variable crustal activity than in typical magnetars. Alternatively, CXO J1852.6+0040 can be in a high state of variable activity during the whole period of observations. Then we consider the source 1E161348 - 5055 in RCW103 as another candidate. Employing a simple 2D-modelling we argue that properties of the source can be explained by the crustal activity of the magnetar type. Thus, this object may be supplemented for the three known candidates for the `hidden' magnetars among central compact objects discussed in literature.

  4. Coupling the inflationary sector to matter

    NASA Astrophysics Data System (ADS)

    Kallosh, Renata; Linde, Andrei; Wrase, Timm

    2016-04-01

    We describe the coupling of matter fields to an inflationary sector of supergravity, the inflaton Φ and a stabilizer S, in models where the Kähler potential has a flat inflaton direction. Such models include, in particular, advanced versions of the hyperbolic α-attractor models with a flat inflaton direction Kähler potential, providing a good fit to the observational data. If the superpotential is at least quadratic in the matter fields U i , with restricted couplings to the inflaton sector, we prove that under certain conditions: i) The presence of the matter fields does not affect a successful inflationary evolution. ii) There are no tachyons in the matter sector during and after inflation. iii) The matter masses squared are higher than 3 H 2 during inflation. The simplest class of theories satisfying all required conditions is provided by models with a flat direction Kähler potential, and with the inflaton Φ and a stabilizer S belonging to a hidden sector, so that matter fields have no direct coupling to the inflationary sector in the Kähler potential and in the superpotential.

  5. Hidden treasures - 50 km points of interests

    NASA Astrophysics Data System (ADS)

    Lommi, Matias; Kortelainen, Jaana

    2015-04-01

    Tampere is third largest city in Finland and a regional centre. During 70's there occurred several communal mergers. Nowadays this local area has both strong and diversed identity - from wilderness and agricultural fields to high density city living. Outside the city center there are interesting geological points unknown for modern city settlers. There is even a local proverb, "Go abroad to Teisko!". That is the area the Hidden Treasures -student project is focused on. Our school Tammerkoski Upper Secondary School (or Gymnasium) has emphasis on visual arts. We are going to offer our art students scientific and artistic experiences and knowledge about the hidden treasures of Teisko area and involve the Teisko inhabitants into this project. Hidden treasures - Precambrian subduction zone and a volcanism belt with dense bed of gold (Au) and arsenic (As), operating goldmines and quarries of minerals and metamorphic slates. - North of subduction zone a homogenic precambrian magmastone area with quarries, products known as Kuru Grey. - Former ashores of post-glasial Lake Näsijärvi and it's sediments enabled the developing agriculture and sustained settlement. Nowadays these ashores have both scenery and biodiversity values. - Old cattle sheds and dairy buildings made of local granite stones related to cultural stonebuilding inheritance. - Local active community of Kapee, about 100 inhabitants. Students will discover information of these "hidden" phenomena, and rendering this information trough Enviromental Art Method. Final form of this project will be published in several artistic and informative geocaches. These caches are achieved by a GPS-based special Hidden Treasures Cycling Route and by a website guiding people to find these hidden points of interests.

  6. 'Hidden' Brain Injury a Challenge for Military Doctors

    MedlinePlus

    ... nih.gov/medlineplus/news/fullstory_159316.html 'Hidden' Brain Injury a Challenge for Military Doctors Potentially fatal ... may suffer from a distinctive pattern of "hidden" brain injury, a small study finds. "Blast-related brain ...

  7. The Second International Conference on Nutrition: Implications for Hidden Hunger.

    PubMed

    Amoroso, Leslie

    2016-01-01

    The Second International Conference on Nutrition (ICN2) was jointly organized by the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO) and was held at the FAO Headquarters in Rome, Italy, from 19 to 21 November 2014. The ICN2 was a high-level intergovernmental meeting that focused global attention on addressing malnutrition in all its forms: undernutrition, including micronutrient deficiencies, overweight, and obesity. The ICN2 was held to specifically address the persistent and unacceptably high levels of malnutrition. Despite much progress in reducing hunger globally, 795 million people remain undernourished, over 2 billion people suffer from various micronutrient deficiencies, and an estimated 161 million children under 5 years of age are stunted, 99 million underweight, and 51 million wasted. Meanwhile, more than 600 million adults are obese. Global problems require global solutions. The ICN2 brought together national policy-makers from food, agriculture, health, education, social protection and other relevant sectors to address the complex problem of malnutrition through a multi-sectoral approach. Two outcome documents - the Rome Declaration on Nutrition and the Framework for Action - were endorsed by participating governments at the Conference, committing world leaders to establishing national policies aimed at eradicating malnutrition in all its forms and transforming food systems to make nutritious diets available to all. The Rome Declaration on Nutrition is a political statement of 10 commitments for more effective and coordinated action to improve nutrition, while the Framework for Action is a voluntary technical guide of 60 recommendations for the implementation of the political commitments. This chapter provides information on the ICN2 and its outcomes as well as follow-up activities. Emphasis is placed on the Rome Declaration on Nutrition and the Framework for Action, with special focus on hidden

  8. Finding an apprenticeship: hidden curriculum and social consequences

    PubMed Central

    Goastellec, Gaële; Ruiz, Guillaume

    2015-01-01

    In Switzerland, the majority of students are oriented toward professional training after compulsory schooling. At this stage, one of the biggest challenges for them is to find an apprenticeship position. Matching supply and demand is a complex process that not only excludes some students from having direct access to professional training but also forces them to make early choices regarding their future sector of employment. So, how does one find an apprenticeship? And what do the students’ descriptions of their search for apprenticeships reveal about the institutional determinants of social inequalities at play in the system? Based on 29 interviews conducted in 2014 with 23 apprentices and 6 recruiters in the Canton of Vaud, this article interrogates how the dimensions of educational and social trajectories combine to affect access to apprenticeships and are accentuated by recruiters using a “hidden curriculum” during the recruitment process. A hidden curriculum consists of knowledge and skills not taught by the educational institution but which appear decisive in obtaining an apprenticeship. By analyzing the contrasting experiences of students in their search for an apprenticeship, we identify four types of trajectories that explain different types of school-to-apprenticeship transitions. We show how these determinants are reinforced by the “hidden curriculum” of recruitment based on the soft skills of feeling, autonomy, anticipation, and reflexivity that are assessed in the context of recruitment interactions. The discussion section debates how the criteria that appear to be used to identify the “right apprentice” tend to (re)produce inequalities between students. This not only depends on their academic results but also on their social and cultural skills, their ability to anticipate their choices and, more widely, their ability to be a subject in their recruitment search. “The Subject is neither the individual, nor the self, but the work through

  9. Gamma rays from hidden millisecond pulsars

    NASA Technical Reports Server (NTRS)

    Tavani, Marco

    1992-01-01

    The properties were studied of a new class of gamma ray sources consisting of millisecond pulsars totally or partially surrounded by evaporating material from irradiated companion stars. Hidden millisecond pulsars offer a unique possibility to study gamma ray, optical and radio emission from vaporizing binaries. The relevance of this class of binaries for GRO observations and interpretation of COS-B data is emphasized.

  10. The Hidden Curriculum of Doctoral Advising

    ERIC Educational Resources Information Center

    Harding-DeKam, Jenni L.; Hamilton, Boni; Loyd, Stacy

    2012-01-01

    We examined the hidden curriculum of doctoral advising by conceptualizing the advisor as a teacher. Using autoethnographic methods in this case study, we simultaneously explored both sides of the advisor-student relationship. The constructivist paradigm permeated all aspects of the research: data collection, analysis, and interpretation. The…

  11. Subtleties of Hidden Quantifiers in Implication

    ERIC Educational Resources Information Center

    Shipman, Barbara A.

    2016-01-01

    Mathematical conjectures and theorems are most often of the form P(x) ? Q(x), meaning ?x,P(x) ? Q(x). The hidden quantifier ?x is crucial in understanding the implication as a statement with a truth value. Here P(x) and Q(x) alone are only predicates, without truth values, since they contain unquantified variables. But standard textbook…

  12. The Hidden Labour Market of the Academic.

    ERIC Educational Resources Information Center

    Rouhelo, Anne

    Finding employment as an academic is becoming increasingly challenging for several reasons, including the tightening employment market and increases in the qualifications demanded of jobseekers and the pool of academically trained job seekers. A two-round Delphi study was therefore conducted to identify recruitment channels in the hidden labor…

  13. Dermatologic hazards from hidden contacts with penicillin.

    PubMed

    Boonk, W J

    1981-01-01

    The unbridled use of penicillin after its discovery by Fleming has resulted in possible hazards to human health due to traces of the drug being present in food and other hidden sources. These hazards may include toxic effects, hypersensitivity reactions and possibly a raising of the frequency and duration of allergy to penicillin. PMID:7028441

  14. Hidden Messages: Instructional Materials for Investigating Culture.

    ERIC Educational Resources Information Center

    Finkelstein, Barbara, Ed.; Eder, Elizabeth K., Ed.

    This book, intended to be used in the middle and high school classroom, provides teachers with unique ideas and lesson plans for exploring culture and adding a multicultural perspective to diverse subjects. "Hidden messages" are the messages of culture that are entwined in everyday lives, but which are seldom recognized or appreciated for the…

  15. Registration of 'Hidden Valley' meadow fescue

    Technology Transfer Automated Retrieval System (TEKTRAN)

    'Hidden Valley' (Reg. No. CV-xxxx, PI xxxxxx) meadow fescue [Schedonorus pratensis (Huds.) P. Beauv.; syn. Festuca pratensis Huds.; syn. Lolium pratense (Huds.) Darbysh.] is a synthetic population originating from 561 parental genotypes. The original germplasm is of unknown central or northern Europ...

  16. Discovering Hidden Treasures with GPS Technology

    ERIC Educational Resources Information Center

    Nagel, Paul; Palmer, Roger

    2014-01-01

    "I found it!" Addison proudly proclaimed, as she used an iPhone and Global Positioning System (GPS) software to find the hidden geocache along the riverbank. Others in Lisa Bostick's fourth grade class were jealous, but there would be other geocaches to find. With the excitement of movies like "Pirates of the Caribbean"…

  17. Hidden Disability and an Academic Career

    ERIC Educational Resources Information Center

    Beretz, Elaine M.

    2003-01-01

    Is fighting a serious illness or recovering from a major injury mutually exclusive with being a professor? Trends in academic employment and societal attitudes toward disability answer that question with a resounding yes. This disturbing state of affairs will continue until people develop ways to accommodate the "hidden" disability of serious…

  18. A Hidden Minority Amidst White Privilege

    ERIC Educational Resources Information Center

    Singer, Miriam J.

    2008-01-01

    It seems rather amusing to say that the author belongs to a minority, no less a hidden minority. After all, at first glance, she appears to be just another white girl (or woman). She grew up in the mid-west in a predominantly white community, middle class, and well educated. The paradox comes in their definition of minority. Today, as they seek to…

  19. Optical probe

    DOEpatents

    Hencken, Kenneth; Flower, William L.

    1999-01-01

    A compact optical probe is disclosed particularly useful for analysis of emissions in industrial environments. The instant invention provides a geometry for optically-based measurements that allows all optical components (source, detector, rely optics, etc.) to be located in proximity to one another. The geometry of the probe disclosed herein provides a means for making optical measurements in environments where it is difficult and/or expensive to gain access to the vicinity of a flow stream to be measured. Significantly, the lens geometry of the optical probe allows the analysis location within a flow stream being monitored to be moved while maintaining optical alignment of all components even when the optical probe is focused on a plurality of different analysis points within the flow stream.

  20. Models of single-molecule experiments with periodic perturbations reveal hidden dynamics in RNA folding.

    PubMed

    Li, Ying; Qu, Xiaohui; Ma, Ao; Smith, Glenna J; Scherer, Norbert F; Dinner, Aaron R

    2009-05-28

    Traditionally, microscopic fluctuations of molecules have been probed by measuring responses of an ensemble to perturbations. Now, single-molecule experiments are capable of following fluctuations without introducing perturbations. However, dynamics not readily sampled at equilibrium should be accessible to nonequilibrium single-molecule measurements. In a recent study [Qu, X. et al. Proc. Natl. Acad. Sci. U.S.A. 2008, 105, 6602-6607], the efficiency of fluorescence resonance energy transfer (FRET) between probes on the L18 loop and 3' terminus of the 260 nucleotide RNase P RNA from Bacillus stearothermophilus was found to exhibit complex kinetics that depended on the (periodically alternating) concentration of magnesium ions ([Mg2+]) in solution. Specifically, this time series was found to exhibit a quasi-periodic response to a square-wave pattern of [Mg2+] changes. Because these experiments directly probe only one of the many degrees of freedom in the macromolecule, models are needed to interpret these data. We find that Hidden Markov Models are inadequate for describing the nonequilibrium dynamics, but they serve as starting points for the construction of models in which a discrete observable degree of freedom is coupled to a continuously evolving (hidden) variable. Consideration of several models of this general form indicates that the quasi-periodic response in the nonequilibrium experiments results from the switching (back and forth) in positions of the minima of the effective potential for the hidden variable. This switching drives oscillation of that variable and synchronizes the population to the changing [Mg2+]. We set the models in the context of earlier theoretical and experimental studies and conclude that single-molecule experiments with periodic peturbations can indeed yield qualitatively new information beyond that obtained at equilibrium. PMID:19415919

  1. Estimating Neuronal Ageing with Hidden Markov Models

    NASA Astrophysics Data System (ADS)

    Wang, Bing; Pham, Tuan D.

    2011-06-01

    Neuronal degeneration is widely observed in normal ageing, meanwhile the neurode-generative disease like Alzheimer's disease effects neuronal degeneration in a faster way which is considered as faster ageing. Early intervention of such disease could benefit subjects with potentials of positive clinical outcome, therefore, early detection of disease related brain structural alteration is required. In this paper, we propose a computational approach for modelling the MRI-based structure alteration with ageing using hidden Markov model. The proposed hidden Markov model based brain structural model encodes intracortical tissue/fluid distribution using discrete wavelet transformation and vector quantization. Further, it captures gray matter volume loss, which is capable of reflecting subtle intracortical changes with ageing. Experiments were carried out on healthy subjects to validate its accuracy and robustness. Results have shown its ability of predicting the brain age with prediction error of 1.98 years without training data, which shows better result than other age predition methods.

  2. Hidden variables and nonlocality in quantum mechanics

    NASA Astrophysics Data System (ADS)

    Hemmick, Douglas Lloyd

    1997-05-01

    Most physicists hold a skeptical attitude toward a 'hidden variables' interpretation of quantum theory, despite David Bohm's successful construction of such a theory and John S. Bell's strong arguments in favor of the idea. The first reason for doubt concerns certain mathematical theorems (von Neumann's, Gleason's, Kochen and Specker's, and Bell's) which can be applied to the hidden variables issue. These theorems are often credited with proving that hidden variables are indeed 'impossible', in the sense that they cannot replicate the predictions of quantum mechanics. Many who do not draw such a strong conclusion nevertheless accept that hidden variables have been shown to exhibit prohibitively complicated features. The second concern is that the most sophisticated example of a hidden variables theory-that of David Bohm-exhibits non-locality, i.e., consequences of events at one place can propagate to other places instantaneously. However, neither the mathematical theorems in question nor the attribute of nonlocality detract from the importance of a hidden variables interpretation of quantum theory. Nonlocality is present in quantum mechanics itself, and is a required characteristic of any theory that agrees with the quantum mechanical predictions. We first discuss the earliest analysis of hidden variables-that of von Neumann's theorem-and review John S. Bell's refutation of von Neumann's 'impossibility proof'. We recall and elaborate on Bell's arguments regarding the theorems of Gleason, and Kochen and Specker. According to Bell, these latter theorems do not imply that hidden variables interpretations are untenable, but instead that such theories must exhibit contextuality, i.e., they must allow for the dependence of measurement results on the characteristics of both measured system and measuring apparatus. We demonstrate a new way to understand the implications of both Gleason's theorem and Kochen and Specker's theorem by noting that they prove a result we call

  3. Extended abstract of a hidden agenda

    SciTech Connect

    Goguen, J.; Malcolm, G.

    1996-12-31

    The initial goal of our hidden research programme was both straightforward and ambitious: give a semantics for software engineering, and in particular for the object paradigm, supporting correctness proofs that are as simple and mechanical as possible. This emphasizes proofs rather than models, and thus suggests an equational approach, rather than one based on higher order logic, denotational semantics, or any kind of model, because equational proofs achieve maximal simplicity and mechanization, and yet are fully expressive. We introduce powerful coinduction techniques for proving behavioral properties of complex systems. We make the no doubt outrageous claim that our hidden approach gives simpler proofs than other formalisms; this is because we exploit algebraic structure that most other approaches discard.

  4. Multiple alignment using hidden Markov models

    SciTech Connect

    Eddy, S.R.

    1995-12-31

    A simulated annealing method is described for training hidden Markov models and producing multiple sequence alignments from initially unaligned protein or DNA sequences. Simulated annealing in turn uses a dynamic programming algorithm for correctly sampling suboptimal multiple alignments according to their probability and a Boltzmann temperature factor. The quality of simulated annealing alignments is evaluated on structural alignments of ten different protein families, and compared to the performance of other HMM training methods and the ClustalW program. Simulated annealing is better able to find near-global optima in the multiple alignment probability landscape than the other tested HMM training methods. Neither ClustalW nor simulated annealing produce consistently better alignments compared to each other. Examination of the specific cases in which ClustalW outperforms simulated annealing, and vice versa, provides insight into the strengths and weaknesses of current hidden Maxkov model approaches.

  5. Hydraulic-Leak Detector for Hidden Joints

    NASA Technical Reports Server (NTRS)

    Anderson, G. E.; Loo, S.

    1986-01-01

    Slow leakage of fluid made obvious. Indicator consists of wick wrapped at one end around joint to be monitored. Wick absorbs hydraulic fluid leaking from joint and transmits to opposite end, located outside cover plate and visible to inspector. Leakage manifested as discoloration of outside end of wick. Indicator reveals leaks in hidden fittings on hydraulic lines. Fast inspection of joints without disassembly. Used in aerospace, petroleum, chemical, nuclear, and other industries where removing covers for inspection impossible, difficult, or time-consuming.

  6. Hidden Markov Model Analysis of Multichromophore Photobleaching

    PubMed Central

    Messina, Troy C.; Kim, Hiyun; Giurleo, Jason T.; Talaga, David S.

    2007-01-01

    The interpretation of single-molecule measurements is greatly complicated by the presence of multiple fluorescent labels. However, many molecular systems of interest consist of multiple interacting components. We investigate this issue using multiply labeled dextran polymers that we intentionally photobleach to the background on a single-molecule basis. Hidden Markov models allow for unsupervised analysis of the data to determine the number of fluorescent subunits involved in the fluorescence intermittency of the 6-carboxy-tetramethylrhodamine labels by counting the discrete steps in fluorescence intensity. The Bayes information criterion allows us to distinguish between hidden Markov models that differ by the number of states, that is, the number of fluorescent molecules. We determine information-theoretical limits and show via Monte Carlo simulations that the hidden Markov model analysis approaches these theoretical limits. This technique has resolving power of one fluorescing unit up to as many as 30 fluorescent dyes with the appropriate choice of dye and adequate detection capability. We discuss the general utility of this method for determining aggregation-state distributions as could appear in many biologically important systems and its adaptability to general photometric experiments. PMID:16913765

  7. Extracting hidden messages in steganographic images

    DOE PAGESBeta

    Quach, Tu-Thach

    2014-07-17

    The eventual goal of steganalytic forensic is to extract the hidden messages embedded in steganographic images. A promising technique that addresses this problem partially is steganographic payload location, an approach to reveal the message bits, but not their logical order. It works by finding modified pixels, or residuals, as an artifact of the embedding process. This technique is successful against simple least-significant bit steganography and group-parity steganography. The actual messages, however, remain hidden as no logical order can be inferred from the located payload. This paper establishes an important result addressing this shortcoming: we show that the expected mean residualsmore » contain enough information to logically order the located payload provided that the size of the payload in each stego image is not fixed. The located payload can be ordered as prescribed by the mean residuals to obtain the hidden messages without knowledge of the embedding key, exposing the vulnerability of these embedding algorithms. We provide experimental results to support our analysis.« less

  8. Extracting hidden messages in steganographic images

    SciTech Connect

    Quach, Tu-Thach

    2014-07-17

    The eventual goal of steganalytic forensic is to extract the hidden messages embedded in steganographic images. A promising technique that addresses this problem partially is steganographic payload location, an approach to reveal the message bits, but not their logical order. It works by finding modified pixels, or residuals, as an artifact of the embedding process. This technique is successful against simple least-significant bit steganography and group-parity steganography. The actual messages, however, remain hidden as no logical order can be inferred from the located payload. This paper establishes an important result addressing this shortcoming: we show that the expected mean residuals contain enough information to logically order the located payload provided that the size of the payload in each stego image is not fixed. The located payload can be ordered as prescribed by the mean residuals to obtain the hidden messages without knowledge of the embedding key, exposing the vulnerability of these embedding algorithms. We provide experimental results to support our analysis.

  9. Atomic-scale wavefunctions and dynamics inside the hidden order compound URu2 Si2

    NASA Astrophysics Data System (ADS)

    Wray, L. Andrew; Denlinger, Jonathan; Huang, Shih-Wen; Butch, Nicholas; Maple, M. Brian; Hussain, Zahid; Chuang, Yi-De

    2015-03-01

    Understanding the emergent wavefunctions of correlated electron systems requires experimental probes that can resolve electronic states on an atomic scale. However, imaging techniques such as STM that resolve single atoms do not provide a good way to distinguish the entangled symmetries of nearby electrons. I will talk about how energy-resolved scattering measurements performed with resonance-tuned X-rays can open a unique window into many-body entangled states on an atomic length scale and femtosecond time scale. The presentation will focus on data that unveil low temperature wavefunction symmetries and energetics of uranium electrons in the ``hidden order'' compound URu2Si2.

  10. Non-statistically populated autoionizing levels of Li-like carbon: Hidden-crossings

    SciTech Connect

    Deveney, E.F.; Krause, H.F.; Jones, N.L.

    1995-12-31

    The intensities of the Auger-electron lines from autoionizing (AI) states of Li-like (1s2s2l) configurations excited in ion-atom collisions vary as functions of the collision parameters such as, for example, the collision velocity. A statistical population of the three-electron levels is at best incomplete and underscores the intricate dynamical development of the electronic states. The authors compare several experimental studies to calculations using ``hidden-crossing`` techniques to explore some of the details of these Auger-electron intensity variation phenomena. The investigations show promising results suggesting that Auger-electron intensity variations can be used to probe collision dynamics.

  11. Hidden extra U(1) at the electroweak/TeV scale

    SciTech Connect

    Grossmann, B. N.; Rai, Santosh Kumar; McElrath, B.; Nandi, S.

    2010-09-01

    We propose a simple extension of the standard model (SM) by adding an extra U(1) symmetry which is hidden from the SM sector. Such a hidden U(1) has not been considered before, and its existence at the TeV scale can be explored at the LHC. This hidden U(1) does not couple directly to the SM particles, and couples only to new SU(2){sub L} singlet exotic quarks and singlet Higgs bosons, and is broken at the TeV scale. The dominant signals at the high-energy hadron colliders are multilepton and multi-b-jet final states with or without missing energy. We calculate the signal rates as well as the corresponding standard model background for these final states. A very distinctive signal is 6 high p{sub T} b-jets in the final state with no missing energy. For a wide range of the exotic quarks masses the signals are observable above the background at the LHC.

  12. Conductivity Probe

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Thermal and Electrical Conductivity Probe (TECP) for NASA's Phoenix Mars Lander took measurements in Martian soil and in the air.

    The needles on the end of the instrument were inserted into the Martian soil, allowing TECP to measure the propagation of both thermal and electrical energy. TECP also measured the humidity in the surrounding air.

    The needles on the probe are 15 millimeters (0.6 inch) long.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  13. Genuinely Multipartite Entangled Quantum States with Fully Local Hidden Variable Models and Hidden Multipartite Nonlocality.

    PubMed

    Bowles, Joseph; Francfort, Jérémie; Fillettaz, Mathieu; Hirsch, Flavien; Brunner, Nicolas

    2016-04-01

    The relation between entanglement and nonlocality is discussed in the case of multipartite quantum systems. We show that, for any number of parties, there exist genuinely multipartite entangled states that admit a fully local hidden variable model, i.e., where all parties are separated. Hence, although these states exhibit the strongest form of multipartite entanglement, they cannot lead to Bell inequality violation considering general nonsequential local measurements. Then, we show that the nonlocality of these states can nevertheless be activated using sequences of local measurements, thus revealing genuine multipartite hidden nonlocality. PMID:27081960

  14. Pollution Probe.

    ERIC Educational Resources Information Center

    Chant, Donald A.

    This book is written as a statement of concern about pollution by members of Pollution Probe, a citizens' anti-pollution group in Canada. Its purpose is to create public awareness and pressure for the eventual solution to pollution problems. The need for effective government policies to control the population explosion, conserve natural resources,…

  15. Microwave background constraints on mixing of photons with hidden photons

    SciTech Connect

    Mirizzi, Alessandro; Redondo, Javier; Sigl, Guenter E-mail: javier.redondo@desy.de

    2009-03-15

    Various extensions of the Standard Model predict the existence of hidden photons kinetically mixing with the ordinary photon. This mixing leads to oscillations between photons and hidden photons, analogous to the observed oscillations between different neutrino flavors. In this context, we derive new bounds on the photon-hidden photon mixing parameters using the high precision cosmic microwave background spectral data collected by the Far Infrared Absolute Spectrophotometer instrument on board of the Cosmic Background Explorer. Requiring the distortions of the CMB induced by the photon-hidden photon mixing to be smaller than experimental upper limits, this leads to a bound on the mixing angle {chi}{sub 0} {approx}< 10{sup -7}-10{sup -5} for hidden photon masses between 10{sup -14} eV and 10{sup -7} eV. This low-mass and low-mixing region of the hidden photon parameter space was previously unconstrained.

  16. Hidden gauged U (1 ) model: Unifying scotogenic neutrino and flavor dark matter

    NASA Astrophysics Data System (ADS)

    Yu, Jiang-Hao

    2016-06-01

    In both scotogenic neutrino and flavor dark matter models, the dark sector communicates with the standard model fermions via Yukawa portal couplings. We propose an economic scenario where the scotogenic neutrino and a flavored mediator share the same inert Higgs doublet and all are charged under a hidden gauged U (1 ) symmetry. The dark Z2 symmetry in the dark sector is regarded as the remnant of this hidden U (1 ) symmetry breaking. In particular, we investigate a dark U (1 )D [and also U (1 )B-L] model which unifies the scotogenic neutrino and top-flavored mediator. Thus dark tops and dark neutrinos are the standard model fermion partners, and the dark matter could be the inert Higgs or the lightest dark neutrino. We note that this model has rich collider signatures on dark tops, the inert Higgs and the Z' gauge boson. Moreover, the scalar associated to the U (1 )D [and also U (1 )B -L ] symmetry breaking could explain the 750 GeV diphoton excess reported by ATLAS and CMS recently.

  17. Hidden photons in Aharonov-Bohm-type experiments

    NASA Astrophysics Data System (ADS)

    Arias, Paola; Diaz, Christian; Diaz, Marco Aurelio; Jaeckel, Joerg; Koch, Benjamin; Redondo, Javier

    2016-07-01

    We discuss the Aharonov-Bohm effect in the presence of hidden photons kinetically mixed with the ordinary electromagnetic photons. The hidden photon field causes a slight phase shift in the observable interference pattern. It is then shown how the limited sensitivity of this experiment can be largely improved. The key observation is that the hidden photon field causes a leakage of the ordinary magnetic field into the supposedly field-free region. The direct measurement of this magnetic field can provide a sensitive experiment with a good discovery potential, particularly below the ˜meV mass range for hidden photons.

  18. Zipf exponent of trajectory distribution in the hidden Markov model

    NASA Astrophysics Data System (ADS)

    Bochkarev, V. V.; Lerner, E. Yu

    2014-03-01

    This paper is the first step of generalization of the previously obtained full classification of the asymptotic behavior of the probability for Markov chain trajectories for the case of hidden Markov models. The main goal is to study the power (Zipf) and nonpower asymptotics of the frequency list of trajectories of hidden Markov frequencys and to obtain explicit formulae for the exponent of the power asymptotics. We consider several simple classes of hidden Markov models. We prove that the asymptotics for a hidden Markov model and for the corresponding Markov chain can be essentially different.

  19. Detecting hidden nodes in complex networks from time series.

    PubMed

    Su, Ri-Qi; Wang, Wen-Xu; Lai, Ying-Cheng

    2012-06-01

    We develop a general method to detect hidden nodes in complex networks, using only time series from nodes that are accessible to external observation. Our method is based on compressive sensing and we formulate a general framework encompassing continuous- and discrete-time and the evolutionary-game type of dynamical systems as well. For concrete demonstration, we present an example of detecting hidden nodes from an experimental social network. Our paradigm for detecting hidden nodes is expected to find applications in a variety of fields where identifying hidden or black-boxed objects based on a limited amount of data is of interest. PMID:23005153

  20. Dual technicolor with hidden local symmetry

    SciTech Connect

    Belitsky, A. V.

    2010-08-15

    We consider a dual description of the technicolor-like gauge theory within the D4/D8-brane configuration with varying confinement and electroweak symmetry breaking scales. Constructing an effective truncated model valid below a certain cutoff, we identify the particle spectrum with Kaluza-Klein modes of the model in a manner consistent with the hidden local symmetry. Integrating out heavy states, we find that the low-energy action receives nontrivial corrections stemming from the mixing between standard model and heavy gauge bosons, which results in reduction of oblique parameters.

  1. Hidden treasure: nurses writing for publication.

    PubMed

    Fry, A

    2000-01-01

    Nurses have a wealth of tacit and explicit knowledge, the value of which remains hidden because of a fear of authorship. How can nurses overcome their intimidation by the pen? In this paper, the personal and intrinsic are integrated with the public and literary as key issues on nurses' authorship are explored. Motivation and disincentives are balanced against helpful strategies for new writers such as cultivating a positive attitude, linking with a critical colleague, consulting 'how to' books, and journal keeping. In addition, originality, creativity, ethics and the shadow side of publishing are discussed. PMID:11855031

  2. Diphoton signals from colorless hidden quarkonia

    NASA Astrophysics Data System (ADS)

    Iwamoto, Sho; Lee, Gabriel; Shadmi, Yael; Ziegler, Robert

    2016-07-01

    We show that quarkonialike states of a hidden SU (N ) gauge group can account for the 750 GeV diphoton excess observed by ATLAS and CMS, even with constituents carrying standard model hypercharge only. The required hypercharge is modest, varying between about 1.3-1.6 for strong SU (N ) coupling to 2-3 for weak SU (N ) coupling, for N =3 , 4. This scenario predicts a variety of diphoton and multiphoton resonances, as well as photons from continuum pair production, and possibly exotic decays into standard model fermions, with no significant multijet resonances.

  3. Diphoton excess as a hidden monopole

    NASA Astrophysics Data System (ADS)

    Yamada, Masaki; Yanagida, Tsutomu T.; Yonekura, Kazuya

    2016-08-01

    We provide a theory with a monopole of a strongly-interacting hidden U(1) gauge symmetry that can explain the 750-GeV diphoton excess reported by ATLAS and CMS. The excess results from the resonance of monopole, which is produced via gluon fusion and decays into two photons. In the low energy, there are only mesons and a monopole in our model because any baryons cannot be gauge invariant in terms of strongly interacting Abelian symmetry. This is advantageous of our model because there is no unwanted relics around the BBN epoch.

  4. Hidden Markov models for stochastic thermodynamics

    NASA Astrophysics Data System (ADS)

    Bechhoefer, John

    2015-07-01

    The formalism of state estimation and hidden Markov models can simplify and clarify the discussion of stochastic thermodynamics in the presence of feedback and measurement errors. After reviewing the basic formalism, we use it to shed light on a recent discussion of phase transitions in the optimized response of an information engine, for which measurement noise serves as a control parameter. The HMM formalism also shows that the value of additional information displays a maximum at intermediate signal-to-noise ratios. Finally, we discuss how systems open to information flow can apparently violate causality; the HMM formalism can quantify the performance gains due to such violations.

  5. A Hidden Markov Model for Urban-Scale Traffic Estimation Using Floating Car Data

    PubMed Central

    Wang, Xiaomeng; Peng, Ling; Chi, Tianhe; Li, Mengzhu; Yao, Xiaojing; Shao, Jing

    2015-01-01

    Urban-scale traffic monitoring plays a vital role in reducing traffic congestion. Owing to its low cost and wide coverage, floating car data (FCD) serves as a novel approach to collecting traffic data. However, sparse probe data represents the vast majority of the data available on arterial roads in most urban environments. In order to overcome the problem of data sparseness, this paper proposes a hidden Markov model (HMM)-based traffic estimation model, in which the traffic condition on a road segment is considered as a hidden state that can be estimated according to the conditions of road segments having similar traffic characteristics. An algorithm based on clustering and pattern mining rather than on adjacency relationships is proposed to find clusters with road segments having similar traffic characteristics. A multi-clustering strategy is adopted to achieve a trade-off between clustering accuracy and coverage. Finally, the proposed model is designed and implemented on the basis of a real-time algorithm. Results of experiments based on real FCD confirm the applicability, accuracy, and efficiency of the model. In addition, the results indicate that the model is practicable for traffic estimation on urban arterials and works well even when more than 70% of the probe data are missing. PMID:26710073

  6. A Hidden Markov Model for Urban-Scale Traffic Estimation Using Floating Car Data.

    PubMed

    Wang, Xiaomeng; Peng, Ling; Chi, Tianhe; Li, Mengzhu; Yao, Xiaojing; Shao, Jing

    2015-01-01

    Urban-scale traffic monitoring plays a vital role in reducing traffic congestion. Owing to its low cost and wide coverage, floating car data (FCD) serves as a novel approach to collecting traffic data. However, sparse probe data represents the vast majority of the data available on arterial roads in most urban environments. In order to overcome the problem of data sparseness, this paper proposes a hidden Markov model (HMM)-based traffic estimation model, in which the traffic condition on a road segment is considered as a hidden state that can be estimated according to the conditions of road segments having similar traffic characteristics. An algorithm based on clustering and pattern mining rather than on adjacency relationships is proposed to find clusters with road segments having similar traffic characteristics. A multi-clustering strategy is adopted to achieve a trade-off between clustering accuracy and coverage. Finally, the proposed model is designed and implemented on the basis of a real-time algorithm. Results of experiments based on real FCD confirm the applicability, accuracy, and efficiency of the model. In addition, the results indicate that the model is practicable for traffic estimation on urban arterials and works well even when more than 70% of the probe data are missing. PMID:26710073

  7. Global Update and Trends of Hidden Hunger, 1995-2011: The Hidden Hunger Index

    PubMed Central

    Stevens, Gretchen A.; Ezzati, Majid; Black, Robert E.; Kraemer, Klaus

    2015-01-01

    Background Deficiencies in essential vitamins and minerals–also termed hidden hunger–are pervasive and hold negative consequences for the cognitive and physical development of children. Methods This analysis evaluates the change in hidden hunger over time in the form of one composite indicator–the Hidden Hunger Index (HHI)–using an unweighted average of prevalence estimates from the Nutrition Impact Model Study for anemia due to iron deficiency, vitamin A deficiency, and stunting (used as a proxy indicator for zinc deficiency). Net changes from 1995–2011 and population weighted regional means for various time periods are measured. Findings Globally, hidden hunger improved (-6.7 net change in HHI) from 1995–2011. Africa was the only region to see a deterioration in hidden hunger (+1.9) over the studied time period; East Asia and the Pacific performed exceptionally well (-13.0), while other regions improved only slightly. Improvements in HHI were mostly due to reductions in zinc and vitamin A deficiencies, while anemia due to iron deficiency persisted and even increased. Interpretation This analysis is critical for informing and tracking the impact of policy and programmatic efforts to reduce micronutrient deficiencies, to advance the global nutrition agenda, and to achieve the Millennium Development Goals (MDGs). However, there remains an unmet need to invest in gathering frequent, nationally representative, high-quality micronutrient data as we renew our efforts to scale up nutrition, and as we enter the post-2015 development agenda. Funding Preparation of this manuscript was funded by Sight and Life. There was no funding involved in the study design, data collection, analysis, or decision to publish. PMID:26673631

  8. Hidden superconformal symmetry of the cosmological evolution

    SciTech Connect

    Kallosh, Renata; Linde, Andrei E-mail: alinde@stanford.edu

    2014-01-01

    In the superconformal formulation of supergravity, the standard supergravity action appears as a result of spontaneous symmetry breaking when the conformal compensator scalar field, the conformon, acquires a nonzero value, giving rise to the Planck mass. After that, many symmetries of the original theory become well hidden, and therefore they are often ignored. However, recent developments demonstrated that superconformal invariance is more than just a tool: it plays an important role in generalizing previously existing formulations of supergravity and developing new classes of inflationary models. In this paper we describe hidden superconformal symmetry of the cosmological evolution. In this formulation, inflation can be equivalently described as the conformon instability, and creation of the universe 'from nothing' can be interpreted as spontaneous symmetry breaking due to emergence of a classical conformon field. We develop a general formalism that allows to describe the cosmological evolution simultaneously with the evolution of the conformon. We find a set of gauge invariant physical observables, including the superconformally invariant generalizations of the square of the Weyl tensor, which are necessary for invariant description of the cosmological singularities.

  9. Hidden percolation transition in kinetic replication process

    NASA Astrophysics Data System (ADS)

    Timonin, P. N.; Chitov, G. Y.

    2015-04-01

    The one-dimensional kinetic contact process with parallel update is introduced and studied by the mean-field approximation and Monte Carlo (MC) simulations. Contrary to a more conventional scenario with single active phase for 1d models with Ising-like variables, we find two different adjacent active phases in the parameter space of the proposed model with a second-order transition between them and a multiphase point where the active and the absorbing phases meet. While one of the active phases is quite standard with a smooth average filling of the space-time lattice, the second active phase demonstrates a very subtle (hidden) percolating order which becomes manifest only after certain transformation from the original model. We determine the percolation order parameter for active-active phase transition and discuss such hidden orders in other low-dimensional systems. Our MC data demonstrate finite-size critical and near-critical scaling of the order parameter relaxation for the two phase transitions. We find three independent critical indices for them and conclude that they both belong to the directed percolation universality class.

  10. Hidden Agendas in Marriage: Affective and Longitudinal Dimensions.

    ERIC Educational Resources Information Center

    Krokoff, Lowell J.

    1990-01-01

    Examines how couples' discussions of troublesome problems reveal hidden agendas (issues not directly discussed or explored). Finds disgust and contempt are at the core of both love and respect agendas for husbands and wives. Finds that wives' more than husbands' hidden agendas are directly predictive of how negatively they argue at home. (SR)

  11. The Hidden Curriculum of Youth Policy: A Dutch Example

    ERIC Educational Resources Information Center

    Hopman, Marit; de Winter, Micha; Koops, Willem

    2014-01-01

    Youth policy is more than a mere response to the actual behavior of children, but it is equally influenced by values and beliefs of policy makers. These values are however rarely made explicit and, therefore, the authors refer to them as "the hidden curriculum" of youth policy. The study investigation explicates this hidden curriculum by…

  12. Hidden Curriculum as One of Current Issue of Curriculum

    ERIC Educational Resources Information Center

    Alsubaie, Merfat Ayesh

    2015-01-01

    There are several issues in the education system, especially in the curriculum field that affect education. Hidden curriculum is one of current controversial curriculum issues. Many hidden curricular issues are the result of assumptions and expectations that are not formally communicated, established, or conveyed within the learning environment.…

  13. Secret Codes: The Hidden Curriculum of Semantic Web Technologies

    ERIC Educational Resources Information Center

    Edwards, Richard; Carmichael, Patrick

    2012-01-01

    There is a long tradition in education of examination of the hidden curriculum, those elements which are implicit or tacit to the formal goals of education. This article draws upon that tradition to open up for investigation the hidden curriculum and assumptions about students and knowledge that are embedded in the coding undertaken to facilitate…

  14. HEALTH SECTOR ASSESSMENT

    EPA Science Inventory

    As part of the USGCRP's First National Assessment effort, EPA's Global Change Research Program sponsored the Health Sector Assessment. The Health Sector Assessment was co-chaired by Dr. Jonathan A. Patz, Director of the Program on the Health Effects of Global Environmental Change...

  15. Combating hidden hunger: the role of international agencies.

    PubMed

    Dalmiya, Nita; Schultink, Werner

    2003-12-01

    The importance of micronutrient deficiencies or "hidden hunger" was clearly emphasized by the inclusion of specific goals on iron, vitamin A, and iodine deficiency at the 1990 World Summit for Children and other major international nutrition conferences. Significant progress has since been made toward eliminating vitamin A and iodine deficiencies, with less progress made toward reducing the burden of iron-deficiency anemia. The role of international agencies, such as the World Health Organization, United Nations Children's Fund, Food and Agricultural Organization, and World Bank in assisting countries to make progress toward the World Summit for Children goals has been very important. International agencies have played a critical role in advocating for and raising awareness of these issues at the international, regional, and national levels among policymakers and the general population. Using a rights-based approach, UNICEF and other agencies have been instrumental in elevating to the highest political level the discussion of every child's right to adequate nutrition. International agencies have also been very supportive at the national level in providing technical guidance for programs, including monitoring and evaluation. These agencies have played a critical role in engaging the cooperation of other partners, including bilateral donors, non-governmental organizations, and the private sector for micronutrient programs. Furthermore, international agencies provide financial and material support for micronutrient programs. In the future, such agencies must continue to be heavily involved in programs to achieve the newly confirmed goals for 2010. The present paper focuses on the role of international agencies in combating micronutrient deficiencies, drawing on the lessons learned over the last decade. The first section of the paper summarizes the progress achieved since 1990, and the second section describes the specific role of international agencies in contributing

  16. Multi-muon events at the Tevatron: a hidden sector from hadronic collisions

    NASA Astrophysics Data System (ADS)

    Barbieri, Riccardo; Hall, Lawrence J.; Rychkov, Vyacheslav S.; Strumia, Alessandro

    2009-11-01

    We show an explicit attempt to interpret the multi-muon anomaly recently claimed by the CDF Collaboration in terms of a light scalar singlet phi which communicates with the standard quarks either through a heavy scalar or a heavy fermion exchange. Building on arXiv:0810.5730, that suggested a singlet phi with a chain decay into a final state made of four \\tau \\bar{\\tau } pairs, we can simulate most of the muon properties of the selected sample of events. Some of these properties adhere rather well to the already published data; others should allow a decisive test of the proposed interpretation. Assuming that the test is positively passed, we show how the PAMELA excess can be fitted by the annihilation of a TeV dark matter particle that communicates with the Standard Model via the new light singlet(s).

  17. Identifying hidden sexual bridging communities in Chicago.

    PubMed

    Youm, Yoosik; Mackesy-Amiti, Mary Ellen; Williams, Chyvette T; Ouellet, Lawrence J

    2009-07-01

    Bridge populations can play a central role in the spread of human immunodeficiency virus (HIV) by providing transmission links between higher and lower prevalence populations. While social network methods are well suited to the study of bridge populations, analyses tend to focus on dyads (i.e., risk between drug and/or sex partners) and ignore bridges between distinct subpopulations. This study takes initial steps toward moving the analysis of sexual network linkages beyond individual and risk group levels to a community level in which Chicago's 77 community areas are examined as subpopulations for the purpose of identifying potential bridging communities. Of particular interest are "hidden" bridging communities; that is, areas with above-average levels of sexual ties with other areas but whose below-average AIDS prevalence may hide their potential importance for HIV prevention. Data for this analysis came from the first wave of recruiting at the Chicago Sexual Acquisition and Transmission of HIV Cooperative Agreement Program site. Between August 2005 through October 2006, respondent-driven sampling was used to recruit users of heroin, cocaine, or methamphetamine, men who have sex with men regardless of drug use, the sex partners of these two groups, and sex partners of the sex partners. In this cross-sectional study of the sexual transmission of HIV, participants completed a network-focused computer-assisted self-administered interview, which included questions about the geographic locations of sexual contacts with up to six recent partners. Bridging scores for each area were determined using a matrix representing Chicago's 77 community areas and were assessed using two measures: non-redundant ties and flow betweenness. Bridging measures and acquired immunodeficiency syndrome (AIDS) case prevalence rates were plotted for each community area on charts representing four conditions: below-average bridging and AIDS prevalence, below-average bridging and above

  18. Geometry underlying no-hidden-variable theorems

    NASA Astrophysics Data System (ADS)

    Fivel, Daniel I.

    1991-07-01

    The set of orientations of a measuring device (e.g., a Stern-Gerlach magnet) produced by the action of a Lie group constitutes a honmogeneous space S (e.g., a sphere). A hidden-variable measure determines a metric D on S, the triangle inequality being Bell's inequality. But identification of S with Hilbert-space projectors induces a locally convex metric d on S. The Einstein-Podolsky-Rosen (EPR) hypotheses imply that D=d2, which is impossible because the square of a locally convex metric cannot be a metric. This proves the Bell-EPR theorem. Classical systems avoid the contradiction by allowing only values d=0,1. The ``watchdog'' effect is shown to result from the form of the quantum-mechanical metric.

  19. Plume mapping via hidden Markov methods.

    PubMed

    Farrell, J A; Pang, Shuo; Li, Wei

    2003-01-01

    This paper addresses the problem of mapping likely locations of a chemical source using an autonomous vehicle operating in a fluid flow. The paper reviews biological plume-tracing concepts, reviews previous strategies for vehicle-based plume tracing, and presents a new plume mapping approach based on hidden Markov methods (HMM). HMM provide efficient algorithms for predicting the likelihood of odor detection versus position, the likelihood of source location versus position, the most likely path taken by the odor to a given location, and the path between two points most likely to result in odor detection. All four are useful for solving the odor source localization problem using an autonomous vehicle. The vehicle is assumed to be capable of detecting above threshold chemical concentration and sensing the fluid flow velocity at the vehicle location. The fluid flow is assumed to vary with space and time, and to have a high Reynolds number (Re>10). PMID:18238238

  20. The hidden biology of sponges and ctenophores.

    PubMed

    Dunn, Casey W; Leys, Sally P; Haddock, Steven H D

    2015-05-01

    Animal evolution is often presented as a march toward complexity, with different living animal groups each representing grades of organization that arose through the progressive acquisition of complex traits. There are now many reasons to reject this classical hypothesis. Not only is it incompatible with recent phylogenetic analyses, but it is also an artifact of 'hidden biology', that is, blind spots to complex traits in non-model species. A new hypothesis of animal evolution, where many complex traits have been repeatedly gained and lost, is emerging. As we discuss here, key details of this new model hinge on a better understanding of the Porifera and Ctenophora, which have each been hypothesized to be sister to all other animals, but are poorly studied and often misrepresented. PMID:25840473

  1. Hidden baryons: The physics of Compton composites

    NASA Astrophysics Data System (ADS)

    Mayer, Frederick J.

    2016-06-01

    A large fraction of the mass-energy of the Universe appears to be composed of Compton composites. How is it then that these composites are not frequently observed in experiments? This paper addresses this question, and others, by reviewing recent publications that: 1) introduced Compton composites, 2) showed how and where they are formed and 3) explained how they interact with other systems. Though ubiquitous in many physical situations, Compton composites are almost completely hidden in experiments due to their unique interaction characteristics. Still, their presence has been indirectly observed, though not interpreted as such until recently. Looking to the future, direct-detection experiments are proposed that could verify the composites' components. It is with deep sadness that I dedicate this paper to my mentor, collaborator, and friend, Dr. John R. Reitz, who passed away within days of the publication of our paper “Compton Composites Late in the Early Universe”.

  2. Probabilistic Resilience in Hidden Markov Models

    NASA Astrophysics Data System (ADS)

    Panerati, Jacopo; Beltrame, Giovanni; Schwind, Nicolas; Zeltner, Stefan; Inoue, Katsumi

    2016-05-01

    Originally defined in the context of ecological systems and environmental sciences, resilience has grown to be a property of major interest for the design and analysis of many other complex systems: resilient networks and robotics systems other the desirable capability of absorbing disruption and transforming in response to external shocks, while still providing the services they were designed for. Starting from an existing formalization of resilience for constraint-based systems, we develop a probabilistic framework based on hidden Markov models. In doing so, we introduce two new important features: stochastic evolution and partial observability. Using our framework, we formalize a methodology for the evaluation of probabilities associated with generic properties, we describe an efficient algorithm for the computation of its essential inference step, and show that its complexity is comparable to other state-of-the-art inference algorithms.

  3. Extracting hidden symmetry from the energy spectrum

    NASA Astrophysics Data System (ADS)

    Yuzbashyan, Emil A.; Happer, William; Altshuler, Boris L.; Shastry, Sriram B.

    2003-03-01

    In this paper we revisit the problem of finding hidden symmetries in quantum mechanical systems. Our interest in this problem was renewed by nontrivial degeneracies of a simple spin Hamiltonian used to model spin relaxation in alkali-metal vapours. We consider this spin Hamiltonian in detail and use this example to outline a general approach to finding symmetries when eigenvalues and eigenstates of the Hamiltonian are known. We extract all nontrivial symmetries responsible for the degeneracy and show that the symmetry group of the Hamiltonian is SU(2). The symmetry operators have a simple meaning which becomes transparent in the limit of large spin. As an additional example we apply the method to the hydrogen atom.

  4. Aluminium Diphosphamethanides: Hidden Frustrated Lewis Pairs.

    PubMed

    Styra, Steffen; Radius, Michael; Moos, Eric; Bihlmeier, Angela; Breher, Frank

    2016-07-01

    The synthesis and characterisation of two aluminium diphosphamethanide complexes, [Al(tBu)2 {κ(2) P,P'-Mes*PCHPMes*}] (3) and [Al(C6 F5 )2 {κ(2) P,P'-Mes*PCHPMes*}] (4), and the silylated analogue, Mes*PCHP(SiMe3 )Mes* (5), are reported. The aluminium complexes feature four-membered PCPAl core structures consisting of diphosphaallyl ligands. The silylated phosphine 5 was found to be a valuable precursor for the synthesis of 4 as it cleanly reacts with the diaryl aluminium chloride [(C6 F5 )2 AlCl]2 . The aluminium complex 3 reacts with molecular dihydrogen at room temperature under formation of the acyclic σ(2) λ(3) ,σ(3) λ(3) -diphosphine Mes*PCHP(H)Mes* and the corresponding dialkyl aluminium hydride [tBu2 AlH]3 . Thus, 3 belongs to the family of so-called hidden frustrated Lewis pairs. PMID:27271936

  5. Mixture Hidden Markov Models in Finance Research

    NASA Astrophysics Data System (ADS)

    Dias, José G.; Vermunt, Jeroen K.; Ramos, Sofia

    Finite mixture models have proven to be a powerful framework whenever unobserved heterogeneity cannot be ignored. We introduce in finance research the Mixture Hidden Markov Model (MHMM) that takes into account time and space heterogeneity simultaneously. This approach is flexible in the sense that it can deal with the specific features of financial time series data, such as asymmetry, kurtosis, and unobserved heterogeneity. This methodology is applied to model simultaneously 12 time series of Asian stock markets indexes. Because we selected a heterogeneous sample of countries including both developed and emerging countries, we expect that heterogeneity in market returns due to country idiosyncrasies will show up in the results. The best fitting model was the one with two clusters at country level with different dynamics between the two regimes.

  6. Magneto-Radar Hidden Metal Detector

    DOEpatents

    McEwan, Thomas E.

    2005-07-05

    A varying magnetic field excites slight vibrations in an object and a radar sensor detects the vibrations at a harmonic of the excitation frequency. The synergy of the magnetic excitation and radar detection provides increased detection range compared to conventional magnetic metal detectors. The radar rejects background clutter by responding only to reflecting objects that are vibrating at a harmonic excitation field, thereby significantly improving detection reliability. As an exemplary arrangement, an ultra-wideband micropower impulse radar (MIR) is capable of being employed to provide superior materials penetration while providing range information. The magneto-radar may be applied to pre-screening magnetic resonance imaging (MRI) patients, landmine detection and finding hidden treasures.

  7. Defect Detection Using Hidden Markov Random Fields

    NASA Astrophysics Data System (ADS)

    Dogandžić, Aleksandar; Eua-anant, Nawanat; Zhang, Benhong

    2005-04-01

    We derive an approximate maximum a posteriori (MAP) method for detecting NDE defect signals using hidden Markov random fields (HMRFs). In the proposed HMRF framework, a set of spatially distributed NDE measurements is assumed to form a noisy realization of an underlying random field that has a simple structure with Markovian dependence. Here, the random field describes the defect signals to be estimated or detected. The HMRF models incorporate measurement locations into the statistical analysis, which is important in scenarios where the same defect affects measurements at multiple locations. We also discuss initialization of the proposed HMRF detector and apply to simulated eddy-current data and experimental ultrasonic C-scan data from an inspection of a cylindrical Ti 6-4 billet.

  8. Natural inflation with hidden scale invariance

    NASA Astrophysics Data System (ADS)

    Barrie, Neil D.; Kobakhidze, Archil; Liang, Shelley

    2016-05-01

    We propose a new class of natural inflation models based on a hidden scale invariance. In a very generic Wilsonian effective field theory with an arbitrary number of scalar fields, which exhibits scale invariance via the dilaton, the potential necessarily contains a flat direction in the classical limit. This flat direction is lifted by small quantum corrections and inflation is realised without need for an unnatural fine-tuning. In the conformal limit, the effective potential becomes linear in the inflaton field, yielding to specific predictions for the spectral index and the tensor-to-scalar ratio, being respectively: ns - 1 ≈ - 0.025(N⋆/60)-1 and r ≈ 0.0667(N⋆/60)-1, where N⋆ ≈ 30- 65 is a number of efolds during observable inflation. This predictions are in reasonable agreement with cosmological measurements. Further improvement of the accuracy of these measurements may turn out to be critical in falsifying our scenario.

  9. Skyrmions with holography and hidden local symmetry

    SciTech Connect

    Nawa, Kanabu; Hosaka, Atsushi; Suganuma, Hideo

    2009-06-15

    We study baryons as Skyrmions in holographic QCD with D4/D8/D8 multi-D brane system in type IIA superstring theory, and also in the nonlinear sigma model with hidden local symmetry. Comparing these two models, we find that the extra dimension and its nontrivial curvature can largely change the role of (axial) vector mesons for baryons in four-dimensional space-time. In the hidden local symmetry approach, the {rho}-meson field as a massive Yang-Mills field has a singular configuration in Skyrmion, which gives a strong repulsion for the baryon as a stabilizer. When the a{sub 1} meson is added in this approach, the stability of Skyrmion is lost by the cancellation of {rho} and a{sub 1} contributions. On the contrary, in holographic QCD, the {rho}-meson field does not appear as a massive Yang-Mills field due to the extra dimension and its nontrivial curvature. We show that the {rho}-meson field has a regular configuration in Skyrmion, which gives a weak attraction for the baryon in holographic QCD. We argue that Skyrmion with {pi}, {rho}, and a{sub 1} mesons become stable due to the curved extra dimension and also the presence of the Skyrme term in holographic QCD. From this result, we also discuss the features of our truncated-resonance analysis on baryon properties with {pi} and {rho} mesons below the cutoff scale M{sub KK}{approx}1 GeV in holographic QCD, which is compared with other 5D instanton analysis.

  10. How hidden are hidden processes? A primer on crypticity and entropy convergence.

    PubMed

    Mahoney, John R; Ellison, Christopher J; James, Ryan G; Crutchfield, James P

    2011-09-01

    We investigate a stationary process's crypticity--a measure of the difference between its hidden state information and its observed information--using the causal states of computational mechanics. Here, we motivate crypticity and cryptic order as physically meaningful quantities that monitor how hidden a hidden process is. This is done by recasting previous results on the convergence of block entropy and block-state entropy in a geometric setting, one that is more intuitive and that leads to a number of new results. For example, we connect crypticity to how an observer synchronizes to a process. We show that the block-causal-state entropy is a convex function of block length. We give a complete analysis of spin chains. We present a classification scheme that surveys stationary processes in terms of their possible cryptic and Markov orders. We illustrate related entropy convergence behaviors using a new form of foliated information diagram. Finally, along the way, we provide a variety of interpretations of crypticity and cryptic order to establish their naturalness and pervasiveness. This is also a first step in developing applications in spatially extended and network dynamical systems. PMID:21974675

  11. How hidden are hidden processes? A primer on crypticity and entropy convergence

    NASA Astrophysics Data System (ADS)

    Mahoney, John R.; Ellison, Christopher J.; James, Ryan G.; Crutchfield, James P.

    2011-09-01

    We investigate a stationary process's crypticity—a measure of the difference between its hidden state information and its observed information—using the causal states of computational mechanics. Here, we motivate crypticity and cryptic order as physically meaningful quantities that monitor how hidden a hidden process is. This is done by recasting previous results on the convergence of block entropy and block-state entropy in a geometric setting, one that is more intuitive and that leads to a number of new results. For example, we connect crypticity to how an observer synchronizes to a process. We show that the block-causal-state entropy is a convex function of block length. We give a complete analysis of spin chains. We present a classification scheme that surveys stationary processes in terms of their possible cryptic and Markov orders. We illustrate related entropy convergence behaviors using a new form of foliated information diagram. Finally, along the way, we provide a variety of interpretations of crypticity and cryptic order to establish their naturalness and pervasiveness. This is also a first step in developing applications in spatially extended and network dynamical systems.

  12. Integrated Radial Probe Transition From MMIC to Waveguide

    NASA Technical Reports Server (NTRS)

    Samoska, Lorene; Chattopadhyay, Goutam

    2007-01-01

    A radial probe transition between a monolithic microwave integrated circuit (MMIC) and a waveguide has been designed for operation at frequency of 340 GHz and to be fabricated as part of a monolithic unit that includes the MMIC. Integrated radial probe transitions like this one are expected to be essential components of future MMIC amplifiers operating at frequencies above 200 GHz. While MMIC amplifiers for this frequency range have not yet been widely used because they have only recently been developed, there are numerous potential applications for them-- especially in scientific instruments, test equipment, radar, and millimeter-wave imaging systems for detecting hidden weapons.

  13. Radio for hidden-photon dark matter detection

    NASA Astrophysics Data System (ADS)

    Chaudhuri, Saptarshi; Graham, Peter W.; Irwin, Kent; Mardon, Jeremy; Rajendran, Surjeet; Zhao, Yue

    2015-10-01

    We propose a resonant electromagnetic detector to search for hidden-photon dark matter over an extensive range of masses. Hidden-photon dark matter can be described as a weakly coupled "hidden electric field," oscillating at a frequency fixed by the mass, and able to penetrate any shielding. At low frequencies (compared to the inverse size of the shielding), we find that the observable effect of the hidden photon inside any shielding is a real, oscillating magnetic field. We outline experimental setups designed to search for hidden-photon dark matter, using a tunable, resonant LC circuit designed to couple to this magnetic field. Our "straw man" setups take into consideration resonator design, readout architecture and noise estimates. At high frequencies, there is an upper limit to the useful size of a single resonator set by 1 /ν . However, many resonators may be multiplexed within a hidden-photon coherence length to increase the sensitivity in this regime. Hidden-photon dark matter has an enormous range of possible frequencies, but current experiments search only over a few narrow pieces of that range. We find the potential sensitivity of our proposal is many orders of magnitude beyond current limits over an extensive range of frequencies, from 100 Hz up to 700 GHz and potentially higher.

  14. Hidden anti-double stranded DNA antibodies in autoimmune mice.

    PubMed Central

    Fish, F; Ziff, M

    1982-01-01

    When MRL/l mouse spleen cell culture supernatants were incubated with normal mouse spleen cells, a two-50-fold increase in anti-dsDNA activity was noted. A smaller increase in anti-ssDNA and no change in anti-TNP antibody activity were observed. This 'hidden' antibody in the MRL/l supernatants could not be revealed by DNAse digestion and could not be absorbed by a DNA cellulose column. Hidden antibody was removed from supernatants by sepharose-anti Ig. After DNAase digestion of the MRL/l supernatants, hidden anti-dsDNA could not be revealed by incubation with spleen cells. All the hidden activity was excluded by gel filtration on Sephacryl S-300 (mol. wt greater than 300,000) but was banded in the low density protein area of caesium chloride equilibrium density gradients. It was also noted that MRL/l mouse sera had hidden anti-dsDNA antibodies. Hidden antibodies were present in both the IgG and IgM classes. The revealed antibodies demonstrated impaired ability to bind Fc specific anti-Ig reagents suggesting that they were partially degraded during the incubation with mouse spleen cells. The hidden anti-dsDNA thus appears to represent a DNA-anti-dsDNA complex, perhaps of very high affinity. It may explain why anti-dsDNA but not anti-ssDNA antibodies are of pathological importance in SLE. PMID:6756722

  15. Radio for hidden-photon dark matter detection

    SciTech Connect

    Chaudhuri, Saptarshi; Graham, Peter W.; Irwin, Kent; Mardon, Jeremy; Rajendran, Surjeet; Zhao, Yue

    2015-10-08

    We propose a resonant electromagnetic detector to search for hidden-photon dark matter over an extensive range of masses. Hidden-photon dark matter can be described as a weakly coupled “hidden electric field,” oscillating at a frequency fixed by the mass, and able to penetrate any shielding. At low frequencies (compared to the inverse size of the shielding), we find that the observable effect of the hidden photon inside any shielding is a real, oscillating magnetic field. We outline experimental setups designed to search for hidden-photon dark matter, using a tunable, resonant LC circuit designed to couple to this magnetic field. Our “straw man” setups take into consideration resonator design, readout architecture and noise estimates. At high frequencies, there is an upper limit to the useful size of a single resonator set by 1/ν. However, many resonators may be multiplexed within a hidden-photon coherence length to increase the sensitivity in this regime. Hidden-photon dark matter has an enormous range of possible frequencies, but current experiments search only over a few narrow pieces of that range. As a result, we find the potential sensitivity of our proposal is many orders of magnitude beyond current limits over an extensive range of frequencies, from 100 Hz up to 700 GHz and potentially higher.

  16. Radio for hidden-photon dark matter detection

    DOE PAGESBeta

    Chaudhuri, Saptarshi; Graham, Peter W.; Irwin, Kent; Mardon, Jeremy; Rajendran, Surjeet; Zhao, Yue

    2015-10-08

    We propose a resonant electromagnetic detector to search for hidden-photon dark matter over an extensive range of masses. Hidden-photon dark matter can be described as a weakly coupled “hidden electric field,” oscillating at a frequency fixed by the mass, and able to penetrate any shielding. At low frequencies (compared to the inverse size of the shielding), we find that the observable effect of the hidden photon inside any shielding is a real, oscillating magnetic field. We outline experimental setups designed to search for hidden-photon dark matter, using a tunable, resonant LC circuit designed to couple to this magnetic field. Ourmore » “straw man” setups take into consideration resonator design, readout architecture and noise estimates. At high frequencies, there is an upper limit to the useful size of a single resonator set by 1/ν. However, many resonators may be multiplexed within a hidden-photon coherence length to increase the sensitivity in this regime. Hidden-photon dark matter has an enormous range of possible frequencies, but current experiments search only over a few narrow pieces of that range. As a result, we find the potential sensitivity of our proposal is many orders of magnitude beyond current limits over an extensive range of frequencies, from 100 Hz up to 700 GHz and potentially higher.« less

  17. Three Dimensional Sector Design with Optimal Number of Sectors

    NASA Technical Reports Server (NTRS)

    Xue, Min

    2010-01-01

    In the national airspace system, sectors get overloaded due to high traffic demand and inefficient airspace designs. Overloads can be eliminated in some cases by redesigning sector boundaries. This paper extends the Voronoi-based sector design method by automatically selecting the number of sectors, allowing three-dimensional partitions, and enforcing traffic pattern conformance. The method was used to design sectors at Fort-Worth and Indianapolis centers for current traffic scenarios. Results show that new designs can eliminate overloaded sectors, although not in all cases, reduce the number of necessary sectors, and conform to major traffic patterns. Overall, the new methodology produces enhanced and efficient sector designs.

  18. Carelessness: A Hidden Doxa of Higher Education

    ERIC Educational Resources Information Center

    Lynch, Kathleen

    2010-01-01

    This article explores the implications of new public sector "reforms" for the culture of higher education. It argues that a culture of carelessness, grounded in Cartesian rationalism, has been exacerbated by new managerialism. The article challenges a prevailing sociological assumption that the character of higher education culture is primarily…

  19. Hidden Fermionic Excitation Boosting High-Temperature Superconductivity in Cuprates

    NASA Astrophysics Data System (ADS)

    Sakai, Shiro; Civelli, Marcello; Imada, Masatoshi

    2016-02-01

    The dynamics of a microscopic cuprate model, namely, the two-dimensional Hubbard model, is studied with a cluster extension of the dynamical mean-field theory. We find a nontrivial structure of the frequency-dependent self-energies, which describes an unprecedented interplay between the pseudogap and superconductivity. We show that these properties are well described by quasiparticles hybridizing with (hidden) fermionic excitations, emergent from the strong electronic correlations. The hidden fermion enhances superconductivity via a mechanism distinct from a conventional boson-mediated pairing, and originates the normal-state pseudogap. Though the hidden fermion is elusive in experiments, it can solve many experimental puzzles.

  20. Hidden Fermionic Excitation Boosting High-Temperature Superconductivity in Cuprates.

    PubMed

    Sakai, Shiro; Civelli, Marcello; Imada, Masatoshi

    2016-02-01

    The dynamics of a microscopic cuprate model, namely, the two-dimensional Hubbard model, is studied with a cluster extension of the dynamical mean-field theory. We find a nontrivial structure of the frequency-dependent self-energies, which describes an unprecedented interplay between the pseudogap and superconductivity. We show that these properties are well described by quasiparticles hybridizing with (hidden) fermionic excitations, emergent from the strong electronic correlations. The hidden fermion enhances superconductivity via a mechanism distinct from a conventional boson-mediated pairing, and originates the normal-state pseudogap. Though the hidden fermion is elusive in experiments, it can solve many experimental puzzles. PMID:26894730

  1. Multilayer neural networks with extensively many hidden units.

    PubMed

    Rosen-Zvi, M; Engel, A; Kanter, I

    2001-08-13

    The information processing abilities of a multilayer neural network with a number of hidden units scaling as the input dimension are studied using statistical mechanics methods. The mapping from the input layer to the hidden units is performed by general symmetric Boolean functions, whereas the hidden layer is connected to the output by either discrete or continuous couplings. Introducing an overlap in the space of Boolean functions as order parameter, the storage capacity is found to scale with the logarithm of the number of implementable Boolean functions. The generalization behavior is smooth for continuous couplings and shows a discontinuous transition to perfect generalization for discrete ones. PMID:11497920

  2. The Italian energy sector

    SciTech Connect

    1997-01-01

    The energy sector in Italy, as in Europe and in many other areas of the world, is undergoing rapid and profound changes. The 1986 ratification of the European Single Act was intended to create a European internal market, where circulation of people, capital, goods, and services would reach the highest possible liberalization. In 1988, in the document The Energy Internal Market, the European Union (EU) commission stressed the need for creation of an internal energy market--free of obstacles--to increase security of supply, to reduce costs, and to strengthen the competitiveness of the European economic system. In 1990, the Community Council adopted directives to implement the EU energy sector. This article describes Italy`s role as part of the EU energy sector. It covers the following topics: the Italian energy sector; electricity vs gas transportation; project finance; recent developments advance Italian power industry; specifying powerplant components -- Italian stype; buyers` guide to Italian equipment, services.

  3. Buildings Sector Analysis

    SciTech Connect

    Hostick, Donna J.; Nicholls, Andrew K.; McDonald, Sean C.; Hollomon, Jonathan B.

    2005-08-01

    A joint NREL, ORNL, and PNNL team conducted market analysis to help inform DOE/EERE's Weatherization and Intergovernmental Program planning and management decisions. This chapter presents the results of the market analysis for the Buildings sector.

  4. ESO's Hidden Treasures Brought to Light

    NASA Astrophysics Data System (ADS)

    2011-01-01

    ESO's Hidden Treasures 2010 astrophotography competition attracted nearly 100 entries, and ESO is delighted to announce the winners. Hidden Treasures gave amateur astronomers the opportunity to search ESO's vast archives of astronomical data for a well-hidden cosmic gem. Astronomy enthusiast Igor Chekalin from Russia won the first prize in this difficult but rewarding challenge - the trip of a lifetime to ESO's Very Large Telescope at Paranal, Chile. The pictures of the Universe that can be seen in ESO's releases are impressive. However, many hours of skilful work are required to assemble the raw greyscale data captured by the telescopes into these colourful images, correcting them for distortions and unwanted signatures of the instrument, and enhancing them so as to bring out the details contained in the astronomical data. ESO has a team of professional image processors, but for the ESO's Hidden Treasures 2010 competition, the experts decided to give astronomy and photography enthusiasts the opportunity to show the world what they could do with the mammoth amount of data contained in ESO's archives. The enthusiasts who responded to the call submitted nearly 100 entries in total - far exceeding initial expectations, given the difficult nature of the challenge. "We were completely taken aback both by the quantity and the quality of the images that were submitted. This was not a challenge for the faint-hearted, requiring both an advanced knowledge of data processing and an artistic eye. We are thrilled to have discovered so many talented people," said Lars Lindberg Christensen, Head of ESO's education and Public Outreach Department. Digging through many terabytes of professional astronomical data, the entrants had to identify a series of greyscale images of a celestial object that would reveal the hidden beauty of our Universe. The chance of a great reward for the lucky winner was enough to spur on the competitors; the first prize being a trip to ESO's Very Large

  5. Solar Sector Structure

    NASA Astrophysics Data System (ADS)

    Hudson, Hugh S.; Svalgaard, Leif; Hannah, Iain G.

    2014-12-01

    The interplanetary magnetic field near 1 AU has a characteristic "sector" structure that reflects its polarity relative to the solar direction. Typically we observe large-scale coherence in these directions, with two or four "away" or "towards" sectors per solar rotation, from any platform in deep space and near the ecliptic plane. In a simple picture, this morphology simply reflects the idea that the sources of the interplanetary field lie mainly in or near the Sun, and that the solar-wind flow enforces a radial component in this field. The sector boundaries are sharply defined in the interplanetary field near one AU, but have more complicated sources within the Sun itself. Recent evidence confirms that the origins of this pattern also appear statistically at the level of the photosphere, with signatures found in the highly concentrated fields of sunspots and even solar flares. This complements the associations already known between the interplanetary sectors and large-scale coronal structures (i.e., the streamers). This association with small-scale fields strengthens at the Hale sector boundary, defining the Hale boundary as the one for which the polarity switch matches that of the leading-to-following polarity alternation in the sunspots of a given hemisphere. Surface features that appear 4.5 days prior to the sector crossings observed at 1 AU correlate with this sense of polarity reversal.

  6. Adolescent Sexuality: Promoting the Search for Hidden Values.

    ERIC Educational Resources Information Center

    DiBlasio, Frederick A.

    1989-01-01

    Adolescent pregnancy and AIDS warrant a reexamination of child welfare workers' professional values toward adolescent sexuality. Presents an exercise designed to assist practitioners in understanding the hidden values that influence intervention. (SAK)

  7. West side, oblique, partially hidden by trees, utility safety fence, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    West side, oblique, partially hidden by trees, utility safety fence, and the deep shadow of the 1962 annex. View to northeast. - San Bernardino Valley College, Library, 701 South Mount Vernon Avenue, San Bernardino, San Bernardino County, CA

  8. Diagnostic Sampling to Reveal Hidden Lead and Copper Health Risks

    EPA Science Inventory

    Lead, copper and other metallic contamination sources in premise drinking water plumbing systems, are unevenly distributed and are usually hidden from thought, view, or both. Many sampling protocols exist, each with some set of implicit assumptions governing its applicability to...

  9. Secret Lives of the Hidden Physicists---from Spandex to Spintronics

    NASA Astrophysics Data System (ADS)

    White, Gary

    2006-10-01

    What is a physicist? A case is made for defining a physicist as anyone with a bachelor's degree (or higher) in physics. Under this definition, a large fraction of physicists are hidden, that is, they have left, or never belonged to, the traditional lot of Ph.D. academicians. Data from the Statistical Research Center at the American Institute of Physics and from a survey of members of the national physics honor society, Sigma Pi Sigma, show the vast array of actual career paths taken by physicists. From spandex to blackberries to bioinformatics to flight control to wind energy to spintronics, physicists can be found in nearly every job sector in some of the coolest and most farfetched careers imaginable.

  10. Shadow Higgs boson from a scale-invariant hidden U(1){sub s} model

    SciTech Connect

    Chang, W.-F.; Ng, John N.; Wu, Jackson M. S.

    2007-06-01

    We study a scale-invariant SU(2)xU(1){sub Y}xU(1){sub s} model which has only dimensionless couplings. The shadow U(1){sub s} is hidden, and it interacts with the standard model (SM) solely through mixing in the scalar sector and kinetic mixing of the U(1) gauge bosons. The gauge symmetries are broken radiatively by the Coleman-Weinberg mechanism. Lifting of the flat direction in the scalar potential gives rise to a light scalar, the scalon, or the shadow Higgs, and a heavier scalar which we identify as the SM Higgs boson. The phenomenology of this model is discussed. In particular, the constraints on the shadow Higgs in different mass ranges, and the possibility of discovering a shadow Higgs with a mass a few tens of GeV in precision t-quark studies at the LHC, are investigated.

  11. An integrated system for identifying the hidden assassins in traditional medicines containing aristolochic acids

    NASA Astrophysics Data System (ADS)

    Wu, Lan; Sun, Wei; Wang, Bo; Zhao, Haiyu; Li, Yaoli; Cai, Shaoqing; Xiang, Li; Zhu, Yingjie; Yao, Hui; Song, Jingyuan; Cheng, Yung-Chi; Chen, Shilin

    2015-08-01

    Traditional herbal medicines adulterated and contaminated with plant materials from the Aristolochiaceae family, which contain aristolochic acids (AAs), cause aristolochic acid nephropathy. Approximately 256 traditional Chinese patent medicines, containing Aristolochiaceous materials, are still being sold in Chinese markets today. In order to protect consumers from health risks due to AAs, the hidden assassins, efficient methods to differentiate Aristolochiaceous herbs from their putative substitutes need to be established. In this study, 158 Aristolochiaceous samples representing 46 species and four genera as well as 131 non-Aristolochiaceous samples representing 33 species, 20 genera and 12 families were analyzed using DNA barcodes based on the ITS2 and psbA-trnH sequences. Aristolochiaceous materials and their non-Aristolochiaceous substitutes were successfully identified using BLAST1, the nearest distance method and the neighbor-joining (NJ) tree. In addition, based on sequence information of ITS2, we developed a Real-Time PCR assay which successfully identified herbal material from the Aristolochiaceae family. Using Ultra High Performance Liquid Chromatography-Mass Spectrometer (UHPLC-HR-MS), we demonstrated that most representatives from the Aristolochiaceae family contain toxic AAs. Therefore, integrated DNA barcodes, Real-Time PCR assays using TaqMan probes and UHPLC-HR-MS system provides an efficient and reliable authentication system to protect consumers from health risks due to the hidden assassins (AAs).

  12. An integrated system for identifying the hidden assassins in traditional medicines containing aristolochic acids

    PubMed Central

    Wu, Lan; Sun, Wei; Wang, Bo; Zhao, Haiyu; Li, Yaoli; Cai, Shaoqing; Xiang, Li; Zhu, Yingjie; Yao, Hui; Song, Jingyuan; Cheng, Yung-Chi; Chen, Shilin

    2015-01-01

    Traditional herbal medicines adulterated and contaminated with plant materials from the Aristolochiaceae family, which contain aristolochic acids (AAs), cause aristolochic acid nephropathy. Approximately 256 traditional Chinese patent medicines, containing Aristolochiaceous materials, are still being sold in Chinese markets today. In order to protect consumers from health risks due to AAs, the hidden assassins, efficient methods to differentiate Aristolochiaceous herbs from their putative substitutes need to be established. In this study, 158 Aristolochiaceous samples representing 46 species and four genera as well as 131 non-Aristolochiaceous samples representing 33 species, 20 genera and 12 families were analyzed using DNA barcodes based on the ITS2 and psbA-trnH sequences. Aristolochiaceous materials and their non-Aristolochiaceous substitutes were successfully identified using BLAST1, the nearest distance method and the neighbor-joining (NJ) tree. In addition, based on sequence information of ITS2, we developed a Real-Time PCR assay which successfully identified herbal material from the Aristolochiaceae family. Using Ultra High Performance Liquid Chromatography-Mass Spectrometer (UHPLC-HR-MS), we demonstrated that most representatives from the Aristolochiaceae family contain toxic AAs. Therefore, integrated DNA barcodes, Real-Time PCR assays using TaqMan probes and UHPLC-HR-MS system provides an efficient and reliable authentication system to protect consumers from health risks due to the hidden assassins (AAs). PMID:26270958

  13. Hidden sources of mercury in clinical laboratories.

    PubMed

    Alvarez-Chavez, C R; Federico-Perez, R A; Gomez-Alvarez, A; Velazquez-Contreras, L E; Perez-Rios, R

    2014-09-01

    The healthcare sector is an important contributor to mercury (Hg) pollution because of the potential presence of mercury in thermometers, blood pressure cuffs, amalgams, etc. There are also other potential sources of mercury in this sector which are used frequently and in high volumes where the presence of the metal is not obvious and which might be collectively contributing to pollution. For instance, some chemicals used for the clinical diagnosis of illness may contain mercury. The goal of this study was to investigate potential sources of mercury pollution, which originate from clinical laboratory discharges, using an exploratory approach. The focus was on the residue generated during automatic analysis of patients' bodily fluids at a medical center in Hermosillo, Sonora, Mexico. This study shows an overview of what might be happening in the region or the country related to non-obvious sources of mercury in the healthcare sector. The results showed measurable levels of mercury in the residues coming from urine sediment analysis. These amounts do not exceed the maximum allowed by Mexican environmental regulations; nevertheless, the frequency and cumulative volume of residues generated, combined with the potential for persistence and the bioaccumulation of mercury in the environment, warrant attention. The work carried out in this study is being taken as a model for future studies for pollution prevention in the healthcare sector with the goal of measuring mercury emissions to the environment from clinical laboratory wastewater, including identifying sources which--while not obvious--could be important given the frequency and volume of their use in the clinical diagnosis. PMID:24816591

  14. Academic mobbing: hidden health hazard at workplace.

    PubMed

    Khoo, Sb

    2010-01-01

    Academic mobbing is a non-violent, sophisticated, 'ganging up' behaviour adopted by academicians to "wear and tear" a colleague down emotionally through unjustified accusation, humiliation, general harassment and emotional abuse. These are directed at the target under a veil of lies and justifications so that they are "hidden" to others and difficult to prove. Bullies use mobbing activities to hide their own weaknesses and incompetence. Targets selected are often intelligent, innovative high achievers, with good integrity and principles. Mobbing activities appear trivial and innocuous on its own but the frequency and pattern of their occurrence over long period of time indicates an aggressive manipulation to "eliminate" the target. Mobbing activities typically progress through five stereotypical phases that begins with an unsolved minor conflict between two workers and ultimately escalates into a senseless mobbing whereby the target is stigmatized and victimized to justify the behaviours of the bullies. The result is always physical, mental, social distress or illness and, most often, expulsion of target from the workplace. Organizations are subjected to great financial loss, loss of key workers and a tarnished public image and reputation. Public awareness, education, effective counselling, establishment of anti-bullying policies and legislations at all levels are necessary to curb academic mobbing. General practitioners (GPs) play an important role in supporting patients subjected to mental and physical health injury caused by workplace bullying and mobbing. PMID:25606190

  15. A Hidden Portrait by Edgar Degas.

    PubMed

    Thurrowgood, David; Paterson, David; de Jonge, Martin D; Kirkham, Robin; Thurrowgood, Saul; Howard, Daryl L

    2016-01-01

    The preservation and understanding of cultural heritage depends increasingly on in-depth chemical studies. Rapid technological advances are forging connections between scientists and arts communities, enabling revolutionary new techniques for non-invasive technical study of culturally significant, highly prized artworks. We have applied a non-invasive, rapid, high definition X-ray fluorescence (XRF) elemental mapping technique to a French Impressionist painting using a synchrotron radiation source, and show how this technology can advance scholarly art interpretation and preservation. We have obtained detailed technical understanding of a painting which could not be resolved by conventional techniques. Here we show 31.6 megapixel scanning XRF derived elemental maps and report a novel image processing methodology utilising these maps to produce a false colour representation of a "hidden" portrait by Edgar Degas. This work provides a cohesive methodology for both imaging and understanding the chemical composition of artworks, and enables scholarly understandings of cultural heritage, many of which have eluded conventional technologies. We anticipate that the outcome from this work will encourage the reassessment of some of the world's great art treasures. PMID:27490856

  16. Hidden Topological Angles in Path Integrals

    NASA Astrophysics Data System (ADS)

    Behtash, Alireza; Sulejmanpasic, Tin; Schäfer, Thomas; Ünsal, Mithat

    2015-07-01

    We demonstrate the existence of hidden topological angles (HTAs) in a large class of quantum field theories and quantum mechanical systems. HTAs are distinct from theta parameters in the Lagrangian. They arise as invariant angles associated with saddle points of the complexified path integral and their descent manifolds (Lefschetz thimbles). Physical effects of HTAs become most transparent upon analytic continuation in nf to a noninteger number of flavors, reducing in the integer nf limit to a Z2 valued phase difference between dominant saddles. In N =1 super Yang-Mills theory we demonstrate the microscopic mechanism for the vanishing of the gluon condensate. The same effect leads to an anomalously small condensate in a QCD-like S U (N ) gauge theory with fermions in the two-index representation. The basic phenomenon is that, contrary to folklore, the gluon condensate can receive both positive and negative contributions in a semiclassical expansion. In quantum mechanics, a HTA leads to a difference in semiclassical expansion of integer and half-integer spin particles.

  17. Hidden Staphylococcus aureus Carriage: Overrated or Underappreciated?

    PubMed Central

    2016-01-01

    ABSTRACT Staphylococcus aureus is a persistent companion bacterial species in one-third of humankind. Reservoirs include the nasal and nasopharyngeal cavities, skin, and gastrointestinal (GI) tract. Despite earlier claims that colonization of individuals is caused by clonal organisms, next-generation sequencing (NGS) has revealed that resident type heterogeneity is not exceptional. Carriage, whether overt or hidden, is correlated with a risk of autoinfection. In a recent article in mBio, it was shown that, based on staphylococcal genome sequencing, low-level GI persistence may cause long-term nosocomial outbreaks [L. Senn et al., 7(1):e02039-15, 2016, doi:10.1128/mBio.02039-15]. Institutional endemicity with methicillin-resistant S. aureus (MRSA) sequence type 228 (ST228) is shown to originate not from high-level nasal carriage or poor compliance with infection control practice but from low-grade asymptomatic GI colonization. This shows the power of NGS in elucidating staphylococcal epidemiology and, even more important, demonstrates that (drug-resistant) microorganisms may possess stealthy means of persistence. Identifying these persistence mechanisms is key to successful infection control. PMID:26884429

  18. Hidden entropy production by fast variables

    NASA Astrophysics Data System (ADS)

    Chun, Hyun-Myung; Noh, Jae Dong

    2015-05-01

    We investigate nonequilibrium underdamped Langevin dynamics of Brownian particles that interact through a harmonic potential with coupling constant K and are in thermal contact with two heat baths at different temperatures. The system is characterized by a net heat flow and an entropy production in the steady state. We compare the entropy production of the harmonic system with that of Brownian particles linked with a rigid rod. The harmonic system may be expected to reduce to the rigid rod system in the infinite K limit. However, we find that the harmonic system in the K →∞ limit produces more entropy than the rigid rod system. The harmonic system has the center-of-mass coordinate as a slow variable and the relative coordinate as a fast variable. By identifying the contributions of the degrees of freedom to the total entropy production, we show that the hidden entropy production by the fast variable is responsible for the extra entropy production. We discuss the K dependence of each contribution.

  19. Homodyne impulse radar hidden object locator

    DOEpatents

    McEwan, Thomas E.

    1996-01-01

    An electromagnetic detector is designed to locate an object hidden behind a separator or a cavity within a solid object. The detector includes a PRF generator for generating 2 MHz pulses, a homodyne oscillator for generating a 2 kHz square wave, and for modulating the pulses from the PRF generator. A transmit antenna transmits the modulated pulses through the separator, and a receive antenna receives the signals reflected off the object. The receiver path of the detector includes a sample and hold circuit, an AC coupled amplifier which filters out DC bias level shifts in the sample and hold circuit, and a rectifier circuit connected to the homodyne oscillator and to the AC coupled amplifier, for synchronously rectifying the modulated pulses transmitted over the transmit antenna. The homodyne oscillator modulates the signal from the PRF generator with a continuous wave (CW) signal, and the AC coupled amplifier operates with a passband centered on that CW signal. The present detector can be used in several applications, including the detection of metallic and non-metallic objects, such as pipes, studs, joists, nails, rebars, conduits and electrical wiring, behind wood wall, ceiling, plywood, particle board, dense hardwood, masonry and cement structure. The detector is portable, light weight, simple to use, inexpensive, and has a low power emission which facilitates the compliance with Part 15 of the FCC rules.

  20. Homodyne impulse radar hidden object locator

    DOEpatents

    McEwan, T.E.

    1996-04-30

    An electromagnetic detector is designed to locate an object hidden behind a separator or a cavity within a solid object. The detector includes a PRF generator for generating 2 MHz pulses, a homodyne oscillator for generating a 2 kHz square wave, and for modulating the pulses from the PRF generator. A transmit antenna transmits the modulated pulses through the separator, and a receive antenna receives the signals reflected off the object. The receiver path of the detector includes a sample and hold circuit, an AC coupled amplifier which filters out DC bias level shifts in the sample and hold circuit, and a rectifier circuit connected to the homodyne oscillator and to the AC coupled amplifier, for synchronously rectifying the modulated pulses transmitted over the transmit antenna. The homodyne oscillator modulates the signal from the PRF generator with a continuous wave (CW) signal, and the AC coupled amplifier operates with a passband centered on that CW signal. The present detector can be used in several applications, including the detection of metallic and non-metallic objects, such as pipes, studs, joists, nails, rebars, conduits and electrical wiring, behind wood wall, ceiling, plywood, particle board, dense hardwood, masonry and cement structure. The detector is portable, light weight, simple to use, inexpensive, and has a low power emission which facilitates the compliance with Part 15 of the FCC rules. 15 figs.

  1. Hidden Markov models for threat prediction fusion

    NASA Astrophysics Data System (ADS)

    Ross, Kenneth N.; Chaney, Ronald D.

    2000-04-01

    This work addresses the often neglected, but important problem of Level 3 fusion or threat refinement. This paper describes algorithms for threat prediction and test results from a prototype threat prediction fusion engine. The threat prediction fusion engine selectively models important aspects of the battlespace state using probability-based methods and information obtained from lower level fusion engines. Our approach uses hidden Markov models of a hierarchical threat state to find the most likely Course of Action (CoA) for the opposing forces. Decision tress use features derived from the CoA probabilities and other information to estimate the level of threat presented by the opposing forces. This approach provides the user with several measures associated with the level of threat, including: probability that the enemy is following a particular CoA, potential threat presented by the opposing forces, and likely time of the threat. The hierarchical approach used for modeling helps us efficiently represent the battlespace with a structure that permits scaling the models to larger scenarios without adding prohibitive computational costs or sacrificing model fidelity.

  2. Phase transitions in Hidden Markov Models

    NASA Astrophysics Data System (ADS)

    Bechhoefer, John; Lathouwers, Emma

    In Hidden Markov Models (HMMs), a Markov process is not directly accessible. In the simplest case, a two-state Markov model ``emits'' one of two ``symbols'' at each time step. We can think of these symbols as noisy measurements of the underlying state. With some probability, the symbol implies that the system is in one state when it is actually in the other. The ability to judge which state the system is in sets the efficiency of a Maxwell demon that observes state fluctuations in order to extract heat from a coupled reservoir. The state-inference problem is to infer the underlying state from such noisy measurements at each time step. We show that there can be a phase transition in such measurements: for measurement error rates below a certain threshold, the inferred state always matches the observation. For higher error rates, there can be continuous or discontinuous transitions to situations where keeping a memory of past observations improves the state estimate. We can partly understand this behavior by mapping the HMM onto a 1d random-field Ising model at zero temperature. We also present more recent work that explores a larger parameter space and more states. Research funded by NSERC, Canada.

  3. Hidden Topological Angles in Path Integrals.

    PubMed

    Behtash, Alireza; Sulejmanpasic, Tin; Schäfer, Thomas; Ünsal, Mithat

    2015-07-24

    We demonstrate the existence of hidden topological angles (HTAs) in a large class of quantum field theories and quantum mechanical systems. HTAs are distinct from theta parameters in the Lagrangian. They arise as invariant angles associated with saddle points of the complexified path integral and their descent manifolds (Lefschetz thimbles). Physical effects of HTAs become most transparent upon analytic continuation in n_{f} to a noninteger number of flavors, reducing in the integer n_{f} limit to a Z_{2} valued phase difference between dominant saddles. In N=1 super Yang-Mills theory we demonstrate the microscopic mechanism for the vanishing of the gluon condensate. The same effect leads to an anomalously small condensate in a QCD-like SU(N) gauge theory with fermions in the two-index representation. The basic phenomenon is that, contrary to folklore, the gluon condensate can receive both positive and negative contributions in a semiclassical expansion. In quantum mechanics, a HTA leads to a difference in semiclassical expansion of integer and half-integer spin particles. PMID:26252675

  4. Stochastic motif extraction using hidden Markov model

    SciTech Connect

    Fujiwara, Yukiko; Asogawa, Minoru; Konagaya, Akihiko

    1994-12-31

    In this paper, we study the application of an HMM (hidden Markov model) to the problem of representing protein sequences by a stochastic motif. A stochastic protein motif represents the small segments of protein sequences that have a certain function or structure. The stochastic motif, represented by an HMM, has conditional probabilities to deal with the stochastic nature of the motif. This HMM directive reflects the characteristics of the motif, such as a protein periodical structure or grouping. In order to obtain the optimal HMM, we developed the {open_quotes}iterative duplication method{close_quotes} for HMM topology learning. It starts from a small fully-connected network and iterates the network generation and parameter optimization until it achieves sufficient discrimination accuracy. Using this method, we obtained an HMM for a leucine zipper motif. Compared to the accuracy of a symbolic pattern representation with accuracy of 14.8 percent, an HMM achieved 79.3 percent in prediction. Additionally, the method can obtain an HMM for various types of zinc finger motifs, and it might separate the mixed data. We demonstrated that this approach is applicable to the validation of the protein databases; a constructed HMM b as indicated that one protein sequence annotated as {open_quotes}lencine-zipper like sequence{close_quotes} in the database is quite different from other leucine-zipper sequences in terms of likelihood, and we found this discrimination is plausible.

  5. Guided ultrasonic wave testing of an immersed plate with hidden defects

    NASA Astrophysics Data System (ADS)

    Bagheri, Abdollah; Rizzo, Piervincenzo

    2016-01-01

    This paper presents the results of an experimental study in which guided ultrasonic waves are used for the contactless nondestructive testing of a plate immersed in water. In the experiment, narrowband leaky Lamb waves are generated using a focused transducer and are detected with an array of five immersion sensors arranged in a semicircle. The ultrasonic signals are processed to extract a few damage-sensitive features from the time and frequency domains. These features are then fed to an artificial neural network to identify the presence of hidden defects, i.e., defects devised on the surface of the plate not facing the probing system. We find that the noncontact inspection system and the signal processing technique enable the classification of the plate health with a success rate >75%.

  6. Local suppression of the hidden-order phase by impurities in URu2Si2

    NASA Astrophysics Data System (ADS)

    Pezzoli, Maria E.; Graf, Matthias J.; Haule, Kristjan; Kotliar, Gabriel; Balatsky, Alexander V.

    2011-06-01

    We consider the effects of impurities on the enigmatic hidden order (HO) state of the heavy-fermion material URu2Si2. In particular, we focus on local effects of Rh impurities as a tool to probe the suppression of the HO state. To study local properties, we introduce a lattice free energy, where the time invariant HO order parameter Ψ and local antiferromagnetic (AFM) order parameter M are competing orders. Near each Rh atom, the HO order parameter is suppressed, creating a hole in which local AFM order emerges as a result of competition. These local holes are created in the fabric of the HO state like in a Swiss cheese and “filled” with droplets of AFM order. We compare our analysis with recent NMR results on U(RhxRu1-x)2Si2 and find good agreement with the data.

  7. The Nuclear Car Wash: Neutron interrogation of cargo containers to detect hidden SNM

    NASA Astrophysics Data System (ADS)

    Hall, J. M.; Asztalos, S.; Biltoft, P.; Church, J.; Descalle, M.-A.; Luu, T.; Manatt, D.; Mauger, G.; Norman, E.; Petersen, D.; Pruet, J.; Prussin, S.; Slaughter, D.

    2007-08-01

    LLNL is actively involved in the development of advanced technologies for use in detecting threats in sea-going cargo containers, particularly the presence of hidden special nuclear materials (SNM). The "Nuclear Car Wash" (NCW) project presented here uses a high-energy (En ≈ 3.5-7.0 MeV) neutron probe to scan a container and then takes high-energy (Eγ ⩾ 2.5 MeV), β-delayed γ-rays emitted during the subsequent decay of any short-lived, neutron-induced fission products as a signature of fissionable material. The components of the proposed system (e.g. neutron source, gamma detectors, etc.) will be discussed along with data processing schemes, possible threat detection metrics and potential interference signals. Results from recent laboratory experiments using a prototype system at LLNL will also be presented.

  8. Sector-scanning echocardiography

    NASA Technical Reports Server (NTRS)

    Henry, W. L.; Griffith, J. M.

    1975-01-01

    The mechanical sector scanner is described in detail, and its clinical application is discussed. Cross sectional images of the heart are obtained in real time using this system. The sector scanner has three major components: (a) hand held scanner, (b) video display, and (c) video recorder. The system provides diagnostic information in a wide spectrum of cardiac diseases, and it quantitates the severity of mitral stenosis by measurement of the mitral valve orifice area in diagnosing infants, children and adults with cyanotic congenital heart disease.

  9. Informatic analysis for hidden pulse attack exploiting spectral characteristics of optics in plug-and-play quantum key distribution system

    NASA Astrophysics Data System (ADS)

    Ko, Heasin; Lim, Kyongchun; Oh, Junsang; Rhee, June-Koo Kevin

    2016-07-01

    Quantum channel loopholes due to imperfect implementations of practical devices expose quantum key distribution (QKD) systems to potential eavesdropping attacks. Even though QKD systems are implemented with optical devices that are highly selective on spectral characteristics, information theory-based analysis about a pertinent attack strategy built with a reasonable framework exploiting it has never been clarified. This paper proposes a new type of trojan horse attack called hidden pulse attack that can be applied in a plug-and-play QKD system, using general and optimal attack strategies that can extract quantum information from phase-disturbed quantum states of eavesdropper's hidden pulses. It exploits spectral characteristics of a photodiode used in a plug-and-play QKD system in order to probe modulation states of photon qubits. We analyze the security performance of the decoy-state BB84 QKD system under the optimal hidden pulse attack model that shows enormous performance degradation in terms of both secret key rate and transmission distance.

  10. Hidden beauty baryon states in the local hidden gauge approach with heavy quark spin symmetry

    NASA Astrophysics Data System (ADS)

    Xiao, C. W.; Oset, E.

    2013-11-01

    Using a coupled-channel unitary approach, combining the heavy quark spin symmetry and the dynamics of the local hidden gauge, we investigate the meson-baryon interaction with hidden beauty and obtain several new states of N around 11 GeV. We consider the basis of states η b N, ϒN, BΛ b , BΣ b , B * Λ b , B * Σ b , B * Σ {/b *} and find four basic bound states which correspond to BΣ b , BΣ {/b *}, B * Σ b and B * Σ {/b *}, decaying mostly into η b N and ϒN and with a binding energy about 50-130 MeV with respect to the thresholds of the corresponding channel. All of them have isospin I = 1/2 , and we find no bound states or resonances in I = 3/2 . The BΣ b state appears in J = 1/2 , the BΣ {/b *} in J = 3/2 , the B * Σ b appears nearly degenerate in J = 1/2 , 3/2 and the B * Σ {/b *} appears nearly degenerate in J = 1/2 , 3/2, 5/2. These states have a width from 2-110 MeV, with conservative estimates of uncertainties, except for the one in J = 5/2 which has zero width since it cannot decay into any of the states of the basis chosen. We make generous estimates of the uncertainties and find that within very large margins these states appear bound.

  11. Primary Dentition Analysis: Exploring a Hidden Approach

    PubMed Central

    Vanjari, Kalasandhya; Kamatham, Rekhalakshmi; Gaddam, Kumar Raja

    2016-01-01

    ABSTRACT Background: Accurate prediction of the mesiodistal widths (MDWs) of canines and premolars in children with primary dentition facilitates interception of malocclusion at an early age. Boston University (BU) approach is one, i.e., based on primary teeth for predicting canine and premolar dimensions. Aim: To predict the canine and premolar dimensions, in the contemporary population, using BU approach and compare with the values obtained using Tanaka-Johnston (T/J) approach. Design: Children in the age range of 7-11 years with presence of all permanent mandibular incisors and primary maxillary and mandibular canines and first molars were included in the study. Those with interproximal caries or restorations, abnormalities in shape or size and history of orthodontic treatment were excluded. Impressions of both arches were made using irreversible hydrocolloid and poured with dental stone. The MDWs of the required teeth were measured on the models using electronic digital vernier caliper from which widths of permanent canines and premolars were predicted using both T/J and BU approaches. Results: Statistically significant (p = 0.00) positive correlation (r = 0.52-0.55) was observed between T/J and BU approaches. A statistically significant (p = 0.00) strong positive correlation (r = 0.72-0.77) was observed among girls, whereas boys showed a statistically nonsignificant weak positive correlation (r=0.17-0.42) based on gender. Conclusion: Boston University approach can be further studied prospectively to make it possible as a prediction method of permanent tooth dimensions for children in primary dentition stage. How to cite this article: Nuvvula S, Vanjari K, Kamatham R, Gaddam KR. Primary Dentition Analysis: Exploring a Hidden Approach. Int J Clin Pediatr Dent 2016;9(1):1-4. PMID:27274146

  12. Foundational Forces & Hidden Variables in Technology Commercialization

    NASA Astrophysics Data System (ADS)

    Barnett, Brandon

    2011-03-01

    The science of physics seems vastly different from the process of technology commercialization. Physics strives to understand our world through the experimental deduction of immutable laws and dependent variables and the resulting macro-scale phenomenon. In comparison, the~goal of business is to make a profit by addressing the needs, preferences, and whims of individuals in a market. It may seem that this environment is too dynamic to identify all the hidden variables and deduct the foundational forces that impact a business's ability to commercialize innovative technologies. One example of a business ``force'' is found in the semiconductor industry. In 1965, Intel co-founder Gordon Moore predicted that the number of transistors incorporated in a chip will approximately double every 24 months. Known as Moore's Law, this prediction has become the guiding principle for the semiconductor industry for the last 40 years. Of course, Moore's Law is not really a law of nature; rather it is the result of efforts by Intel and the entire semiconductor industry. A closer examination suggests that there are foundational principles of business that underlie the macro-scale phenomenon of Moore's Law. Principles of profitability, incentive, and strategic alignment have resulted in a coordinated influx of resources that has driven technologies to market, increasing the profitability of the semiconductor industry and optimizing the fitness of its participants. New innovations in technology are subject to these same principles. So, in addition to traditional market forces, these often unrecognized forces and variables create challenges for new technology commercialization. In this talk, I will draw from ethnographic research, complex adaptive theory, and industry data to suggest a framework with which to think about new technology commercialization. Intel's bio-silicon initiative provides a case study.

  13. Peptide crystal simulations reveal hidden dynamics

    PubMed Central

    Janowski, Pawel A.; Cerutti, David S.; Holton, James; Case, David A.

    2013-01-01

    Molecular dynamics simulations of biomolecular crystals at atomic resolution have the potential to recover information on dynamics and heterogeneity hidden in the X-ray diffraction data. We present here 9.6 microseconds of dynamics in a small helical peptide crystal with 36 independent copies of the unit cell. The average simulation structure agrees with experiment to within 0.28 Å backbone and 0.42 Å all-atom rmsd; a model refined against the average simulation density agrees with the experimental structure to within 0.20 Å backbone and 0.33 Å all-atom rmsd. The R-factor between the experimental structure factors and those derived from this unrestrained simulation is 23% to 1.0 Å resolution. The B-factors for most heavy atoms agree well with experiment (Pearson correlation of 0.90), but B-factors obtained by refinement against the average simulation density underestimate the coordinate fluctuations in the underlying simulation where the simulation samples alternate conformations. A dynamic flow of water molecules through channels within the crystal lattice is observed, yet the average water density is in remarkable agreement with experiment. A minor population of unit cells is characterized by reduced water content, 310 helical propensity and a gauche(−) side-chain rotamer for one of the valine residues. Careful examination of the experimental data suggests that transitions of the helices are a simulation artifact, although there is indeed evidence for alternate valine conformers and variable water content. This study highlights the potential for crystal simulations to detect dynamics and heterogeneity in experimental diffraction data, as well as to validate computational chemistry methods. PMID:23631449

  14. Identifying hidden voice and video streams

    NASA Astrophysics Data System (ADS)

    Fan, Jieyan; Wu, Dapeng; Nucci, Antonio; Keralapura, Ram; Gao, Lixin

    2009-04-01

    Given the rising popularity of voice and video services over the Internet, accurately identifying voice and video traffic that traverse their networks has become a critical task for Internet service providers (ISPs). As the number of proprietary applications that deliver voice and video services to end users increases over time, the search for the one methodology that can accurately detect such services while being application independent still remains open. This problem becomes even more complicated when voice and video service providers like Skype, Microsoft, and Google bundle their voice and video services with other services like file transfer and chat. For example, a bundled Skype session can contain both voice stream and file transfer stream in the same layer-3/layer-4 flow. In this context, traditional techniques to identify voice and video streams do not work. In this paper, we propose a novel self-learning classifier, called VVS-I , that detects the presence of voice and video streams in flows with minimum manual intervention. Our classifier works in two phases: training phase and detection phase. In the training phase, VVS-I first extracts the relevant features, and subsequently constructs a fingerprint of a flow using the power spectral density (PSD) analysis. In the detection phase, it compares the fingerprint of a flow to the existing fingerprints learned during the training phase, and subsequently classifies the flow. Our classifier is not only capable of detecting voice and video streams that are hidden in different flows, but is also capable of detecting different applications (like Skype, MSN, etc.) that generate these voice/video streams. We show that our classifier can achieve close to 100% detection rate while keeping the false positive rate to less that 1%.

  15. The hidden price of repeated traumatic exposure.

    PubMed

    Levy-Gigi, Einat; Richter-Levin, Gal

    2014-07-01

    Neuroimaging studies have demonstrated reduced hippocampal volume in trauma-exposed individuals without posttraumatic stress disorder (PTSD). However, the implications of such a deficit in this non-clinical population are still unclear. Animal and human models of PTSD suggest that hippocampal deficit may result in impaired learning and use of associations between contextual information and aversive events. Previous study has shown that individuals with PTSD have a selective impairment in reversing the negative outcome of context-related information. The aim of this study was to test whether non-PTSD individuals who are repeatedly exposed to traumatic events display similar impairment. To that end, we compared the performance of active-duty firefighters who are frequently exposed to traumatic events as part of their occupational routine and civilian matched-controls with no history of trauma-exposure. We used a novel cue-context reversal paradigm, which separately evaluates reversal of negative and positive outcomes of cue and context-related information. As predicted, we found that while both trauma-exposed firefighters and unexposed matched-controls were able to acquire and retain stimulus-outcome associations, firefighters struggled to learn that a previously negative context is later associated with a positive outcome. This impairment did not correlate with levels of PTSD, anxiety or depressive symptoms. The results suggest that similar to individuals with PTSD, highly exposed individuals fail to associate traumatic outcomes with their appropriate context. This impairment may reflect a possible hidden price of repeated traumatic exposure, which is not necessarily associated with PTSD diagnosis, and may affect the way highly exposed individuals interpret and react to their environment. PMID:24810272

  16. VISTA Captures Celestial Cat's Hidden Secrets

    NASA Astrophysics Data System (ADS)

    2010-04-01

    The Cat's Paw Nebula, NGC 6334, is a huge stellar nursery, the birthplace of hundreds of massive stars. In a magnificent new ESO image taken with the Visible and Infrared Survey Telescope for Astronomy (VISTA) at the Paranal Observatory in Chile, the glowing gas and dust clouds obscuring the view are penetrated by infrared light and some of the Cat's hidden young stars are revealed. Towards the heart of the Milky Way, 5500 light-years from Earth in the constellation of Scorpius (the Scorpion), the Cat's Paw Nebula stretches across 50 light-years. In visible light, gas and dust are illuminated by hot young stars, creating strange reddish shapes that give the object its nickname. A recent image by ESO's Wide Field Imager (WFI) at the La Silla Observatory (eso1003) captured this visible light view in great detail. NGC 6334 is one of the most active nurseries of massive stars in our galaxy. VISTA, the latest addition to ESO's Paranal Observatory in the Chilean Atacama Desert, is the world's largest survey telescope (eso0949). It works at infrared wavelengths, seeing right through much of the dust that is such a beautiful but distracting aspect of the nebula, and revealing objects hidden from the sight of visible light telescopes. Visible light tends to be scattered and absorbed by interstellar dust, but the dust is nearly transparent to infrared light. VISTA has a main mirror that is 4.1 metres across and it is equipped with the largest infrared camera on any telescope. It shares the spectacular viewing conditions with ESO's Very Large Telescope (VLT), which is located on the nearby summit. With this powerful instrument at their command, astronomers were keen to see the birth pains of the big young stars in the Cat's Paw Nebula, some nearly ten times the mass of the Sun. The view in the infrared is strikingly different from that in visible light. With the dust obscuring the view far less, they can learn much more about how these stars form and develop in their first

  17. VISTA Captures Celestial Cat's Hidden Secrets

    NASA Astrophysics Data System (ADS)

    2010-04-01

    The Cat's Paw Nebula, NGC 6334, is a huge stellar nursery, the birthplace of hundreds of massive stars. In a magnificent new ESO image taken with the Visible and Infrared Survey Telescope for Astronomy (VISTA) at the Paranal Observatory in Chile, the glowing gas and dust clouds obscuring the view are penetrated by infrared light and some of the Cat's hidden young stars are revealed. Towards the heart of the Milky Way, 5500 light-years from Earth in the constellation of Scorpius (the Scorpion), the Cat's Paw Nebula stretches across 50 light-years. In visible light, gas and dust are illuminated by hot young stars, creating strange reddish shapes that give the object its nickname. A recent image by ESO's Wide Field Imager (WFI) at the La Silla Observatory (eso1003) captured this visible light view in great detail. NGC 6334 is one of the most active nurseries of massive stars in our galaxy. VISTA, the latest addition to ESO's Paranal Observatory in the Chilean Atacama Desert, is the world's largest survey telescope (eso0949). It works at infrared wavelengths, seeing right through much of the dust that is such a beautiful but distracting aspect of the nebula, and revealing objects hidden from the sight of visible light telescopes. Visible light tends to be scattered and absorbed by interstellar dust, but the dust is nearly transparent to infrared light. VISTA has a main mirror that is 4.1 metres across and it is equipped with the largest infrared camera on any telescope. It shares the spectacular viewing conditions with ESO's Very Large Telescope (VLT), which is located on the nearby summit. With this powerful instrument at their command, astronomers were keen to see the birth pains of the big young stars in the Cat's Paw Nebula, some nearly ten times the mass of the Sun. The view in the infrared is strikingly different from that in visible light. With the dust obscuring the view far less, they can learn much more about how these stars form and develop in their first

  18. Public Sector Impasse Procedures.

    ERIC Educational Resources Information Center

    Vadakin, James C.

    The subject of collective bargaining negotiation impasse procedures in the public sector, which includes public school systems, is a broad one. In this speech, the author introduces the various procedures, explains how they are used, and lists their advantages and disadvantages. Procedures discussed are mediation, fact-finding, arbitration,…

  19. Hydrodynamic ultrasonic probe

    DOEpatents

    Day, Robert A.; Conti, Armond E.

    1980-01-01

    An improved probe for in-service ultrasonic inspection of long lengths of a workpiece, such as small diameter tubing from the interior. The improved probe utilizes a conventional transducer or transducers configured to inspect the tubing for flaws and/or wall thickness variations. The probe utilizes a hydraulic technique, in place of the conventional mechanical guides or bushings, which allows the probe to move rectilinearly or rotationally while preventing cocking thereof in the tube and provides damping vibration of the probe. The probe thus has lower friction and higher inspection speed than presently known probes.

  20. Detection of hidden explosives in different scenarios with the use of nuclear probes

    NASA Astrophysics Data System (ADS)

    Nebbia, G.; Pesente, S.; Lunardon, M.; Moretto, S.; Viesti, G.; Cinausero, M.; Barbui, M.; Fioretto, E.; Filippini, V.; Sudac, D.; Nađ, K.; Blagus, S.; Valković, V.

    2005-04-01

    The detection of landmines by using available technologies is a time consuming, expensive and extremely dangerous job, so that there is a need for a technological breakthrough in this field. Atomic and nuclear physics based sensors might offer new possibilities in de-mining. Technology and methods derived from the studies applied to the detection of landmines can be successfully applied to the screening of cargo in customs inspections.

  1. Future Trends in Chlldren's Web Pages: Probing Hidden Biases for Information Quality

    ERIC Educational Resources Information Center

    Kurubacak, Gulsun

    2007-01-01

    As global digital communication continues to flourish, Children's Web pages become more critical for children to realize not only the surface but also breadth and deeper meanings in presenting these milieus. These pages not only are very diverse and complex but also enable intense communication across social, cultural and political restrictions…

  2. Future Trends in Children's Web Pages: Probing Hidden Biases for Information Quality

    ERIC Educational Resources Information Center

    Kurubacak, Gulsun

    2007-01-01

    As global digital communication continues to flourish, Children's Web pages become more critical for children to realize not only the surface but also breadth and deeper meanings in presenting these milieus. These pages not only are very diverse and complex but also enable intense communication across social, cultural and political restrictions…

  3. Reputation and Competition in a Hidden Action Model

    PubMed Central

    Fedele, Alessandro; Tedeschi, Piero

    2014-01-01

    The economics models of reputation and quality in markets can be classified in three categories. (i) Pure hidden action, where only one type of seller is present who can provide goods of different quality. (ii) Pure hidden information, where sellers of different types have no control over product quality. (iii) Mixed frameworks, which include both hidden action and hidden information. In this paper we develop a pure hidden action model of reputation and Bertrand competition, where consumers and firms interact repeatedly in a market with free entry. The price of the good produced by the firms is contractible, whilst the quality is noncontractible, hence it is promised by the firms when a contract is signed. Consumers infer future quality from all available information, i.e., both from what they know about past quality and from current prices. According to early contributions, competition should make reputation unable to induce the production of high-quality goods. We provide a simple solution to this problem by showing that high quality levels are sustained as an outcome of a stationary symmetric equilibrium. PMID:25329387

  4. Reputation and competition in a hidden action model.

    PubMed

    Fedele, Alessandro; Tedeschi, Piero

    2014-01-01

    The economics models of reputation and quality in markets can be classified in three categories. (i) Pure hidden action, where only one type of seller is present who can provide goods of different quality. (ii) Pure hidden information, where sellers of different types have no control over product quality. (iii) Mixed frameworks, which include both hidden action and hidden information. In this paper we develop a pure hidden action model of reputation and Bertrand competition, where consumers and firms interact repeatedly in a market with free entry. The price of the good produced by the firms is contractible, whilst the quality is noncontractible, hence it is promised by the firms when a contract is signed. Consumers infer future quality from all available information, i.e., both from what they know about past quality and from current prices. According to early contributions, competition should make reputation unable to induce the production of high-quality goods. We provide a simple solution to this problem by showing that high quality levels are sustained as an outcome of a stationary symmetric equilibrium. PMID:25329387

  5. Infinite hidden conditional random fields for human behavior analysis.

    PubMed

    Bousmalis, Konstantinos; Zafeiriou, Stefanos; Morency, Louis-Philippe; Pantic, Maja

    2013-01-01

    Hidden conditional random fields (HCRFs) are discriminative latent variable models that have been shown to successfully learn the hidden structure of a given classification problem (provided an appropriate validation of the number of hidden states). In this brief, we present the infinite HCRF (iHCRF), which is a nonparametric model based on hierarchical Dirichlet processes and is capable of automatically learning the optimal number of hidden states for a classification task. We show how we learn the model hyperparameters with an effective Markov-chain Monte Carlo sampling technique, and we explain the process that underlines our iHCRF model with the Restaurant Franchise Rating Agencies analogy. We show that the iHCRF is able to converge to a correct number of represented hidden states, and outperforms the best finite HCRFs--chosen via cross-validation--for the difficult tasks of recognizing instances of agreement, disagreement, and pain. Moreover, the iHCRF manages to achieve this performance in significantly less total training, validation, and testing time. PMID:24808217

  6. Hidden Behavior Prediction of Complex Systems Based on Hybrid Information.

    PubMed

    Zhou, Zhi-Jie; Hu, Chang-Hua; Zhang, Bang-Cheng; Xu, Dong-Ling; Chen, Yu-Wang

    2013-04-01

    It is important to predict both observable and hidden behaviors in complex engineering systems. However, compared with observable behavior, it is often difficult to establish a forecasting model for hidden behavior. The existing methods for predicting the hidden behavior cannot effectively and simultaneously use the hybrid information with uncertainties that include qualitative knowledge and quantitative data. Although belief rule base (BRB) has been employed to predict the observable behavior using the hybrid information with uncertainties, it is still not applicable to predict the hidden behavior directly. As such, in this paper, a new BRB-based model is proposed to predict the hidden behavior. In the proposed BRB-based model, the initial values of parameters are usually given by experts, thus some of them may not be accurate, which can lead to inaccurate prediction results. In order to solve the problem, a parameter estimation algorithm for training the parameters of the forecasting model is further proposed on the basis of maximum likelihood algorithm. Using the hybrid information with uncertainties, the proposed model can combine together with the parameter estimation algorithm and improve the forecasting precision in an integrated and effective manner. A case study is conducted to demonstrate the capability and potential applications of the proposed forecasting model with the parameter estimation algorithm. PMID:22907969

  7. Hidden Statistics Approach to Quantum Simulations

    NASA Technical Reports Server (NTRS)

    Zak, Michail

    2010-01-01

    Recent advances in quantum information theory have inspired an explosion of interest in new quantum algorithms for solving hard computational (quantum and non-quantum) problems. The basic principle of quantum computation is that the quantum properties can be used to represent structure data, and that quantum mechanisms can be devised and built to perform operations with this data. Three basic non-classical properties of quantum mechanics superposition, entanglement, and direct-product decomposability were main reasons for optimism about capabilities of quantum computers that promised simultaneous processing of large massifs of highly correlated data. Unfortunately, these advantages of quantum mechanics came with a high price. One major problem is keeping the components of the computer in a coherent state, as the slightest interaction with the external world would cause the system to decohere. That is why the hardware implementation of a quantum computer is still unsolved. The basic idea of this work is to create a new kind of dynamical system that would preserve the main three properties of quantum physics superposition, entanglement, and direct-product decomposability while allowing one to measure its state variables using classical methods. In other words, such a system would reinforce the advantages and minimize limitations of both quantum and classical aspects. Based upon a concept of hidden statistics, a new kind of dynamical system for simulation of Schroedinger equation is proposed. The system represents a modified Madelung version of Schroedinger equation. It preserves superposition, entanglement, and direct-product decomposability while allowing one to measure its state variables using classical methods. Such an optimal combination of characteristics is a perfect match for simulating quantum systems. The model includes a transitional component of quantum potential (that has been overlooked in previous treatment of the Madelung equation). The role of the

  8. Hidden caring, hidden carers? Exploring the experience of carers for people with long-term conditions.

    PubMed

    Knowles, Sarah; Combs, Ryan; Kirk, Sue; Griffiths, May; Patel, Neesha; Sanders, Caroline

    2016-03-01

    Informal carers make a significant contribution to illness management in communities, but many struggle to access support and remain 'hidden carers'. We aimed to explore how carers of people with common long-term conditions (LTCs, such as coronary heart disease or kidney disease) conceptualised their caring, and whether they struggled to identify themselves with the term 'carer' or access for support. We conducted semi-structured interviews with 19 informal carers of people with LTCs recruited from local support groups. Topic guides were designed to encourage participants to provide their retrospective accounts of identifying as a carer or struggling to do so. Data were analysed using the constant comparative method. The study was designed collaboratively with a patient and public involvement (PPI) partner, and we consulted with a PPI steering group of people with lived experience of caring during the study. Results showed how participants drew on comparisons with those caring for more dependent relatives in explaining their reluctance to define themselves as a carer, and resisted adopting the label due to concerns that it would threaten the identity of the cared-for person. The data were interpreted in terms of types of 'work' undertaken to manage LTCs, and revealed that carers of patients with LTCs appear to primarily engage in biographical and emotional support, which may be more difficult to conceptualise as legitimate caring 'work'. Participants indicated that health professionals may be in a unique position to validate their role as carers and encourage support seeking. The study suggests how the greater focus on self-management of LTCs in the community must be complemented by recognition of this group as potentially 'hidden carers', who support the patient to minimise the impact the illness has on their lives and consequently may minimise their own caring role, with negative implications for support seeking. PMID:25706665

  9. Translational science and the hidden research system in universities and academic hospitals: a case study.

    PubMed

    Lander, Bryn; Atkinson-Grosjean, Janet

    2011-02-01

    Innovation systems (IS) and science policy scholarship predominantly focus on linkages between universities and industry, and the commercial translation of academic discoveries. Overlooked in such analyses are important connections between universities and academic hospitals, and the non-commercial aspects of translational science. The two types of institutions tend to be collapsed into a single entity-'the university'-and relational flows are lost. Yet the distinctions and flows between the two are crucial elements of translational science and the biomedical innovation system. This paper explores what has been called the 'hidden research system' that connects hospitals, universities, and their resources, with the clinical and scientific actors who make the linkages possible. Then, using a novel conceptual model of translational science, we examine the individual interactions and dynamics involved in a particular example of the biomedical innovation system at work: the diagnosis of IRAK-4 deficiency, a rare immunological disorder, and the translational flows that result. Contra to conventional IS analyses, we are able to point to the strong role of public-sector institutions, and the weak role of the private-sector, in the translational processes described here. Our research was conducted within a Canadian network of scientists and clinician-scientists studying the pathogenomics of immunological disorders and innate immunity. PMID:21168250

  10. Detection and tracking of moving objects hidden from view

    NASA Astrophysics Data System (ADS)

    Gariepy, Genevieve; Tonolini, Francesco; Henderson, Robert; Leach, Jonathan; Faccio, Daniele

    2016-01-01

    The ability to detect motion and track a moving object hidden around a corner or behind a wall provides a crucial advantage when physically going around the obstacle is impossible or dangerous. Previous methods have demonstrated that it is possible to reconstruct the shape of an object hidden from view. However, these methods do not enable the tracking of movement in real time. We demonstrate a compact non-line-of-sight laser ranging technology that relies on the ability to send light around an obstacle using a scattering floor and then detect the return signal from a hidden object within only a few seconds of acquisition time. By detecting this signal with a single-photon avalanche diode (SPAD) camera, we follow the movement of an object located a metre away from the camera with centimetre precision. We discuss the possibility of applying this technology to a variety of real-life situations in the near future.