WorldWideScience

Sample records for spontaneous polarisation field

  1. Nucleon Polarisabilities and Effective Field Theories

    Science.gov (United States)

    Griesshammer, Harald W.

    2017-09-01

    Low-energy Compton scattering probes the nucleon's two-photon response to electric and magnetic fields at fixed photon frequency and multipolarity. It tests the symmetries and strengths of the interactions between constituents, and with photons. For convenience, this energy-dependent information is often compressed into the two scalar dipole polarisabilities αE 1 and βM 1 at zero photon energy. These are fundamental quantities, and important for the proton charge radius puzzle and the Lamb shift of muonic hydrogen. Combined with emerging lattice QCD computations, they provide stringent tests for our understanding of hadron structure. Extractions of the proton and neutron polarisabilities from all published elastic data below 300 MeV in Chiral Effective Field Theory with explicit Δ (1232) are now available. This talk emphasises χEFT as natural bridge between lattice QCD and ongoing or approved efforts at HI γS, MAMI and MAX-lab. Chiral lattice extrapolations from mπ > 200 MeV to the physical point compare well to lattice computations. Combining χEFT with high-intensity experiments with polarised targets and polarised beams will extract not only scalar polarisabilities, but in particular the four so-far poorly explored spin-polarisabilities. These parametrise the stiffness of the spin in external electro-magnetic fields (nucleonic bi-refringence/Faraday effect). New chiral predictions for proton, deuteron and 3He observables show intriguing sensitivities on spin and neutron polarisabilities. Data consistency and a model-independent quantification of residual theory uncertainties by Bayesian analysis are also discussed. Proton-neutron differences explore the interplay between chiral symmetry breaking and short-distance Physics. Finally, I address their impact on the neutron-proton mass difference, big-bang nucleosynthesis, and their relevance for anthropic arguments. Supported in part by DOE DE-SC0015393 and George Washington University.

  2. Vacuum polarisation in some static nonuniform magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Calucci, G. [Trieste Univ. (Italy). Dip. di Fisica Teorica]|[INFN, Trieste (Italy)

    1995-11-01

    Vacuum polarisation in QED in presence of some configurations of external magnetic fields is investigated. The configuration considered correspond to fields is investigated. The configuration considered correspond to fields lying in a plane and without sources. The motion of a Dirac electron in this field configuration is studied and arguments are found to conclude that the lowest level gives the most important contribution. The result is that the main effect is not very different from the uniform case, the possibilities of calculating the corrections due to the uniformity is explicitly shown. A typical effect of nonuniformity of the field shows out in the refractivity of the field shows out in the refractivity of the vacuum.

  3. Vacuum polarisation in some static nonuniform magnetic fields

    International Nuclear Information System (INIS)

    Calucci, G.

    1995-11-01

    Vacuum polarisation in QED in presence of some configurations of external magnetic fields is investigated. The configuration considered correspond to fields is investigated. The configuration considered correspond to fields lying in a plane and without sources. The motion of a Dirac electron in this field configuration is studied and arguments are found to conclude that the lowest level gives the most important contribution. The result is that the main effect is not very different from the uniform case, the possibilities of calculating the corrections due to the uniformity is explicitly shown. A typical effect of nonuniformity of the field shows out in the refractivity of the field shows out in the refractivity of the vacuum

  4. Polarisation of the spontaneous emission from nonpolar and semipolar InGaN quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Schade, Lukas; Schwarz, Ulrich [Department of Microsystems Engineering, University of Freiburg (IMTEK) (Germany); Fraunhofer Institute for Applied Solid State Physics (IAF) (Germany); Ploch, Simon; Wernicke, Tim [Institute of Solid State Physics, Technical University Berlin (Germany); Knauer, Arne; Hoffmann, Veit; Weyers, Markus [Ferdinand-Braun-Institute (FBH) (Germany); Kneissl, Michael [Institute of Solid State Physics, Technical University Berlin (Germany); Ferdinand-Braun-Institute (FBH) (Germany)

    2011-07-01

    Spontaneously emitted light stemming from semipolar and nonpolar InGaN quantum wells is polarized. This property is a consequence of the broken in-plane symmetry of non c-plane wurtzite quantum wells. We studied the polarized photoluminescence of semipolar and nonpolar InGaN/InGaN multi quantum wells grown on low defect density GaN substrates with a setup for confocal microscopy. For excitation of charge carriers we use a 375 nm diode laser. The photoluminescence is collected with an objective of small NA, to avoid polarisation scrambling, and analyzed with a broadband polarizer and a spectrometer. The experimental results are compared to k.p band structure calculations for semipolar and nonpolar InGaN quantum wells. These simulations provide the polarisation degree of the confined states of the valence band and their energetic splitting. Next, from the thermal occupation the polarized spectra are calculated. The comparison with experimental results allows the determination of the valence subband splitting. Our experiments show a splitting of the two topmost valence subbands in nonpolar direction which is larger than predicted.

  5. Evidence from optical polarisation for a galactic-scale uniform magnetic field in M104

    International Nuclear Information System (INIS)

    Scarrott, S.M.; White, C.; Pallister, W.S.; Solinger, A.B.

    1977-01-01

    A map is presented of the linear optical polarisation of the Sombrero Galaxy (M104) that gives clear evidence for the existence of a magnetic field that maintains the same projected direction over an estimated volume of some 10 3 kpc 3 . Detailed knowledge of the polarisation pattern in a nebula is stated to be a powerful tool for further understanding of a nebula. The observations described were made with the 1 m telescope of the Wise Observatory, Israel, during May 1976 using the B waveband of the UBV system, together with a polarimeter and a 4 cm electronographic camera. Measurements were made at 1000 points within the galaxy. The map is superimposed on a photograph of M104, and its main features are described. It is stated that there is little doubt that the observed polarisation pattern was due to the scattering and extinction of light by statistically aligned dust grains. The alignment of the grains is most probably due to magnetic effects, and unless some unexpected mechanism is occurring the grains must be magnetically aligned. The findings are discussed. It is stated that the fact that scattering from aligned grains is occurring makes M104 a likely candidate for the observation of circular polarisation, and such an observation would tend to confirm the interpretation of the linear polarisation. It seems that the observations are concerned with the most extensive homogeneous magnetic field so far observed and it is tempting to speculate that it may be primordial in origin. (U.K.)

  6. Intra-well relaxation process in magnetic fluids subjected to strong polarising fields

    Energy Technology Data Exchange (ETDEWEB)

    Marin, C.N., E-mail: cmarin@physics.uvt.ro [West University of Timisoara, Faculty of Physics, B-dul V. Parvan, No. 4, Timisoara 300223 (Romania); Fannin, P.C. [Department of Electronic and Electrical Engineering, Trinity College, Dublin 2 (Ireland); Malaescu, I.; Barvinschi, P.; Ercuta, A. [West University of Timisoara, Faculty of Physics, B-dul V. Parvan, No. 4, Timisoara 300223 (Romania)

    2012-02-15

    We report on the frequency and field dependent complex magnetic susceptibility measurements of a kerosene-based magnetic fluid with iron oxide nanoparticles, stabilized with oleic acid, in the frequency range 0.1-6 GHz and over the polarising field range of 0-168.4 kA/m. By increasing polarising field, H, a subsidiary loss-peak clearly occurs in the vicinity of the ferromagnetic resonance peak, from which it remains distinct even in strong polarising fields of 168.4 kA/m. This is in contrast to other reported cases in which the intra-well relaxation process is manifested only as a shoulder of the resonance peak, which vanishes in polarising fields larger than that of 100 kA/m. The results of the XRD analysis connected to the anisotropy field results confirm that the investigated sample contains particles of magnetite and of the tetragonal phase of maghemite. Taking into account the characteristics of our sample, the theoretical analysis revealed that the intra-well relaxation process of the small particles of the tetragonal phase of maghemite may be responsible for the subsidiary loss peak of the investigated magnetic fluid. - Highlights: > Intra-well relaxation process in a magnetic fluid is studied. > Sample consists of the tetragonal phase of maghemite and magnetite particles. > A subsidiary relaxation peak is observed in the vicinity of the resonance peak. > Relaxation peak is correlated to the intra-well relaxation process. > It is assigned to the tetragonal phase of maghemite particles.

  7. Polarised Multiangular Reflectance Measurements Using the Finnish Geodetic Institute Field Goniospectrometer

    Directory of Open Access Journals (Sweden)

    Jouni Peltoniemi

    2009-05-01

    Full Text Available The design, operation, and properties of the Finnish Geodetic Institute Field Goniospectrometer (FIGIFIGO are presented. FIGIFIGO is a portable instrument for the measurement of surface Bidirectional Reflectance Factor (BRF for samples with diameters of 10 – 50 cm. A set of polarising optics enable the measurement of linearly polarised BRF over the full solar spectrum (350 – 2,500 nm. FIGIFIGO is designed mainly for field operation using sunlight, but operation in a laboratory environment is also possible. The acquired BRF have an accuracy of 1 – 5% depending on wavelength, sample properties, and measurement conditions. The angles are registered at accuracies better than 2°. During 2004 – 2008, FIGIFIGO has been used in the measurement of over 150 samples, all around northern Europe. The samples concentrate mostly on boreal forest understorey, snow, urban surfaces, and reflectance calibration surfaces.

  8. The invariant polarisation-tensor field for deuterons in storage rings and the Bloch equation for the polarisation-tensor density

    International Nuclear Information System (INIS)

    Barber, D.P.

    2015-10-01

    I extend and update earlier work, summarised in an earlier paper (D.P. Barber, M. Voigt, AIP Conference Proceedings 1149 (28)), whereby the invariant polarisation-tensor field (ITF) for deuterons in storage rings was introduced to complement the invariant spin field (ISF). Taken together, the ITF and the ISF provide a definition of the equilibrium spin density-matrix field which, in turn, offers a clean framework for describing equilibrium spin-1 ensembles in storage rings. I show how to construct the ITF by stroboscopic averaging, I give examples, I discuss adiabatic invariance and I introduce a formalism for describing the effect of noise and damping.

  9. Design of an electrically small circularly polarised turnstile antenna and its application to near-field wireless power transfer

    DEFF Research Database (Denmark)

    Yoon, Ick-Jae; Ling, Hao

    2014-01-01

    An electrically small circularly polarised antenna is designed and applied to near-field wireless power transfer as a means of alleviating orientation dependence. The antenna is miniaturised from a spl lambda//2-turnstile antenna by utilising the top loading and multiple folding techniques. A loc...... performance is verified in the far field. The power transfer efficiency is then examined in the near field via simulation and measurement. It is shown that the designed circularly polarised antenna is effective in mitigating orientation dependence down to a distance of 0.2λ.......An electrically small circularly polarised antenna is designed and applied to near-field wireless power transfer as a means of alleviating orientation dependence. The antenna is miniaturised from a spl lambda//2-turnstile antenna by utilising the top loading and multiple folding techniques. A local...... numerical search is used to determine the optimal antenna dimensions to achieve good axial ratio and impedance matching. The resulting design has a kr of 0.67 and shows good circular polarisation characteristic with a 3% axial ratio bandwidth. The designed antenna is fabricated and its circular polarisation...

  10. A polarisation modulation scheme for measuring vacuum magnetic birefringence with static fields

    Energy Technology Data Exchange (ETDEWEB)

    Zavattini, G.; Ejlli, A. [Universita di Ferrara, Dipt. di Fisica e Scienze della Terra (Italy); INFN, Sezione di Ferrara (Italy); Della Valle, F. [Universita di Trieste, Dipt. di Fisica, Trieste (Italy); INFN, Sezione di Trieste, TS (Italy); Ruoso, G. [INFN, Lab. Nazionali di Legnaro (Italy)

    2016-05-15

    A novel polarisation modulation scheme for polarimeters based on Fabry-Perot cavities is presented. The application to the measurement of the magnetic birefringence of vacuum with the HERA superconducting magnets in the ALPS-II configuration is discussed. (orig.)

  11. IN5 Polarisation Option (IPOP) and HIgh FIeld Magnet Option (HIFIMO) for the IN5 time-of-flight spectrometer

    International Nuclear Information System (INIS)

    Ollivier, J.; Mutka, H.

    2011-01-01

    The new secondary spectrometer for the cold neutron time-of-flight (ToF) instrument IN5 was built with non-magnetic material, keeping in mind the upgrade option of polarisation analysis (PA) and the possibility of applying high continuous magnetic fields. The refurbished instrument has a high incident flux and elevated count-rate and offers a unique opportunity for applying polarised neutron methods for high resolution inelastic scattering, including single crystal investigations. On IN5 the polarised option would use the PASTIS concept of three sets of compact perpendicular coils (see the PANTHER proposal) allowing XYZPA and a 3 He analyser banana. As for high magnetic fields: a magnet suitable for ToF instruments must place a minimal amount of material in the incoming and outgoing beams and provide a large asymmetric view towards the detectors. An homogeneous field area of about 20 mm diameter over 30 mm height is also required. There is a size constraint set by the 800 mm diameter sample chamber and the optimal angular acceptance towards the detectors is -12 degrees / +135 degrees in the equatorial plane and +/- 22 degrees in the vertical direction

  12. Spontaneous electric fields in solid films: spontelectrics

    DEFF Research Database (Denmark)

    Field, David; Plekan, Oksana; Cassidy, Andrew

    2013-01-01

    When dipolar gases are condensed at sufficiently low temperature onto a solid surface, they form films that may spontaneously exhibit electric fields in excess of 108V/m. This effect, called the ‘spontelectric effect’, was recently revealed using an instrument designed to measure scattering....... Heterolayers may also be laid down creating potential wells on the nanoscale. A model is put forward based upon competition between dipole alignment and thermal disorder, which is successful in reproducing the variation of the degree of dipole alignment and the spontelectric field with deposition temperature...

  13. Polarisation confirmed

    CERN Multimedia

    Anaïs Schaeffer

    2014-01-01

    The polarisation of photons emitted in the decay of a bottom quark into a strange quark, as predicted by the Standard Model, has just been observed for the first time by the LHCb collaboration. More detailed research is still required to determine the value of this polarisation with precision.   In this LHCb event, K, π and γ are emitted from a B+ → K+π-π+γ decay. This was investigated by the LHCb collaboration in order to study the photon (γ) polarisation.   If we imagine that photons are like little spinning tops which spin around an axis aligned with their direction of propagation, we can identify two types of photons. Those that are “right-handed” turn in the same direction as a corkscrew, and those that are “left-handed” turn in the opposite direction. If for a large number of decays of a given type we can observe an imbalance between the production of right-han...

  14. Effect of ferromagnetic exchange field on band gap and spin polarisation of graphene on a TMD substrate

    Science.gov (United States)

    Goswami, Partha

    2018-03-01

    We calculate the electronic band dispersion of graphene monolayer on a two-dimensional transition metal dichalcogenide substrate (GrTMD) around K and K^' } points by taking into account the interplay of the ferromagnetic impurities and the substrate-induced interactions. The latter are (strongly enhanced) intrinsic spin-orbit interaction (SOI), the extrinsic Rashba spin-orbit interaction (RSOI) and the one related to the transfer of the electronic charge from graphene to substrate. We introduce exchange field ( M) in the Hamiltonian to take into account the deposition of magnetic impurities on the graphene surface. The cavalcade of the perturbations yield particle-hole symmetric band dispersion with an effective Zeeman field due to the interplay of the substrate-induced interactions with RSOI as the prime player. Our graphical analysis with extremely low-lying states strongly suggests the following: The GrTMDs, such as graphene on WY2, exhibit (direct) band-gap narrowing / widening (Moss-Burstein (MB) gap shift) including the increase in spin polarisation ( P) at low temperature due to the increase in the exchange field ( M) at the Dirac points. The polarisation is found to be electric field tunable as well. Finally, there is anticrossing of non-parabolic bands with opposite spins, the gap closing with same spins, etc. around the Dirac points. A direct electric field control of magnetism at the nanoscale is needed here. The magnetic multiferroics, like BiFeO3 (BFO), are useful for this purpose due to the coupling between the magnetic and electric order parameters.

  15. Thermal neutron polarisation

    International Nuclear Information System (INIS)

    Satya Murthy, N.S.; Madhava Rao, L.

    1984-01-01

    The basic principle for the production of polarised thermal neutrons is discussed and the choice of various crystal monochromators surveyed. Brief mention of broad-spectrum polarisers is made. The application of polarised neutrons to the study of magnetisation density distributions in magnetic crystals, the dynamic concept of polarisation, principle and use of polarisation analysis, the neutron spin-echo technique are discussed. (author)

  16. Constrained Gauge Fields from Spontaneous Lorentz Violation

    CERN Document Server

    Chkareuli, J L; Jejelava, J G; Nielsen, H B

    2008-01-01

    Spontaneous Lorentz violation realized through a nonlinear vector field constraint of the type $A_{\\mu}^{2}=M^{2}$ ($M$ is the proposed scale for Lorentz violation) is shown to generate massless vector Goldstone bosons, gauging the starting global internal symmetries in arbitrary relativistically invariant theories. The gauge invariance appears in essence as a necessary condition for these bosons not to be superfluously restricted in degrees of freedom, apart from the constraint due to which the true vacuum in a theory is chosen by the Lorentz violation. In the Abelian symmetry case the only possible theory proves to be QED with a massless vector Goldstone boson naturally associated with the photon, while the non-Abelian symmetry case results in a conventional Yang-Mills theory. These theories, both Abelian and non-Abelian, look essentially nonlinear and contain particular Lorentz (and $CPT$) violating couplings when expressed in terms of the pure Goldstone vector modes. However, they do not lead to physical ...

  17. Constrained gauge fields from spontaneous Lorentz violation

    DEFF Research Database (Denmark)

    Chkareuli, J. L.; Froggatt, C. D.; Jejelava, J. G.

    2008-01-01

    Spontaneous Lorentz violation realized through a nonlinear vector field constraint of the type AµAµ=M2 (M is the proposed scale for Lorentz violation) is shown to generate massless vector Goldstone bosons, gauging the starting global internal symmetries in arbitrary relativistically invariant...... theories. The gauge invariance appears in essence as a necessary condition for these bosons not to be superfluously restricted in degrees of freedom, apart from the constraint due to which the true vacuum in a theory is chosen by the Lorentz violation. In the Abelian symmetry case the only possible theory...... couplings when expressed in terms of the pure Goldstone vector modes. However, they do not lead to physical Lorentz violation due to the simultaneously generated gauge invariance. Udgivelsesdato: June 11...

  18. FEL gain optimisation and spontaneous radiation

    Energy Technology Data Exchange (ETDEWEB)

    Bali, L.M.; Srivastava, A.; Pandya, T.P. [Lucknow Univ. (India)] [and others

    1995-12-31

    Colson have evaluated FEL gains for small deviations from perfect electron beam injection, with radiation of the same polarisation as that of the wiggler fields. We find that for optimum gain the polarisation of the optical field should be the same as that of the spontaneous emission under these conditions. With a helical wiggler the axial oscillations resulting from small departures from perfect electron beam injection lead to injection dependent unequal amplitudes and phases of the spontaneous radiation in the two transverse directions. Viewed along the axis therefore the spontaneous emission is elliptically polarised. The azimuth of the ellipse varies with the difference of phase of the two transverse components of spontaneous emission but the eccentricity remains the same. With planar wigglers the spontaneous emission viewed in the axial direction is linearly polarised, again with an injection dependent azimuth. For optimum coherent gain of a radiation field its polarisation characteristics must be the same as those of the spontaneous radiation with both types of wiggler. Thus, with a helical wiggler and the data reported earlier, an increase of 10% in the FEL gain at the fundamental frequency and of 11% at the fifth harmonic has been calculated in the small gain per pass limit. Larger enhancements in gain may result from more favourable values of input parameters.

  19. Static nuclear polarisation and polarised targets

    International Nuclear Information System (INIS)

    Heeringa, W.

    1984-12-01

    Recent progress and status of statically polarised nuclear targets are reviewed. Special attention is given to polarised 1 H and 3 He. An important quantity in the determination of the target polarisation is the thermal gradient over the target sample. The dependence of this gradient on heat input, sample geometry, and thermal conductivity of the sample is discussed. Possibilities of performing experiments with proton beams are indicated. (orig.) [de

  20. Three dimensional magnetohydrodynamic simulation of linearly polarised Alfven wave dynamics in Arnold-Beltrami-Childress magnetic field

    International Nuclear Information System (INIS)

    Tsiklauri, D.

    2014-01-01

    Previous studies (e.g., Malara et al., Astrophys. J. 533, 523 (2000)) considered small-amplitude Alfven wave (AW) packets in Arnold-Beltrami-Childress (ABC) magnetic field using WKB approximation. They draw a distinction between 2D AW dissipation via phase mixing and 3D AW dissipation via exponentially divergent magnetic field lines. In the former case, AW dissipation time scales as S 1∕3 and in the latter as log(S), where S is the Lundquist number. In this work, linearly polarised Alfven wave dynamics in ABC magnetic field via direct 3D magnetohydrodynamic (MHD) numerical simulation is studied for the first time. A Gaussian AW pulse with length-scale much shorter than ABC domain length and a harmonic AW with wavelength equal to ABC domain length are studied for four different resistivities. While it is found that AWs dissipate quickly in the ABC field, contrary to an expectation, it is found the AW perturbation energy increases in time. In the case of the harmonic AW, the perturbation energy growth is transient in time, attaining peaks in both velocity and magnetic perturbation energies within timescales much smaller than the resistive time. In the case of the Gaussian AW pulse, the velocity perturbation energy growth is still transient in time, attaining a peak within few resistive times, while magnetic perturbation energy continues to grow. It is also shown that the total magnetic energy decreases in time and this is governed by the resistive evolution of the background ABC magnetic field rather than AW damping. On contrary, when the background magnetic field is uniform, the total magnetic energy decrease is prescribed by AW damping, because there is no resistive evolution of the background. By considering runs with different amplitudes and by analysing the perturbation spectra, possible dynamo action by AW perturbation-induced peristaltic flow and inverse cascade of magnetic energy have been excluded. Therefore, the perturbation energy growth is attributed to

  1. Three dimensional magnetohydrodynamic simulation of linearly polarised Alfven wave dynamics in Arnold-Beltrami-Childress magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Tsiklauri, D. [School of Physics and Astronomy, Queen Mary University of London, London E1 4NS (United Kingdom)

    2014-05-15

    Previous studies (e.g., Malara et al., Astrophys. J. 533, 523 (2000)) considered small-amplitude Alfven wave (AW) packets in Arnold-Beltrami-Childress (ABC) magnetic field using WKB approximation. They draw a distinction between 2D AW dissipation via phase mixing and 3D AW dissipation via exponentially divergent magnetic field lines. In the former case, AW dissipation time scales as S{sup 1∕3} and in the latter as log(S), where S is the Lundquist number. In this work, linearly polarised Alfven wave dynamics in ABC magnetic field via direct 3D magnetohydrodynamic (MHD) numerical simulation is studied for the first time. A Gaussian AW pulse with length-scale much shorter than ABC domain length and a harmonic AW with wavelength equal to ABC domain length are studied for four different resistivities. While it is found that AWs dissipate quickly in the ABC field, contrary to an expectation, it is found the AW perturbation energy increases in time. In the case of the harmonic AW, the perturbation energy growth is transient in time, attaining peaks in both velocity and magnetic perturbation energies within timescales much smaller than the resistive time. In the case of the Gaussian AW pulse, the velocity perturbation energy growth is still transient in time, attaining a peak within few resistive times, while magnetic perturbation energy continues to grow. It is also shown that the total magnetic energy decreases in time and this is governed by the resistive evolution of the background ABC magnetic field rather than AW damping. On contrary, when the background magnetic field is uniform, the total magnetic energy decrease is prescribed by AW damping, because there is no resistive evolution of the background. By considering runs with different amplitudes and by analysing the perturbation spectra, possible dynamo action by AW perturbation-induced peristaltic flow and inverse cascade of magnetic energy have been excluded. Therefore, the perturbation energy growth is

  2. Social polarisation in Aarhus

    DEFF Research Database (Denmark)

    Christensen, Anders Bøggild

    This paper is connected to the phd. project: “Social polarisation in Aarhus” and will discuss the concept of social polarisation and related concepts as poverty, marginalization and social exclusion in developing a research strategy in studying social polarisation in the city....

  3. Axions and polarisation of quasars

    International Nuclear Information System (INIS)

    Payez, A.; Cudell, J. R.; Hutsemekers, D.

    2008-01-01

    We present results showing that, thanks to axion-photon mixing in external magnetic fields, it is actually possible to produce an effect similar to the one needed to explain the large-scale coherent orientations of quasar polarisation vectors in visible light that have been observed in some regions of the sky

  4. Macroscopic influence on the spontaneous symmetry breaking in quantum field

    International Nuclear Information System (INIS)

    Kirzhnitz, D.A.

    1977-01-01

    Major results of investigations concerning macroscopic influence (heating, compression, external field and current) on elementary particle systems with spontaneous symmetry breaking are briefly reviewed. The study of this problem has been stimulated by recent progress in the unified renormalizable theory of elementary particles. Typically it appears that at some values of external parameters a phase transition with symmetry restoration takes place. There exists a profound and far going analogy with phase transition in many-body physics especially with superconductivity phenomenon. Some applications to cosmology are also considered

  5. Development of an thin, internal superconducting polarisation magnet for the polarised target

    Energy Technology Data Exchange (ETDEWEB)

    Altfelde, Timo; Bornstein, Marcel; Dutz, Hartmut; Goertz, Stefan; Miebach, Roland; Reeve, Scott; Runkel, Stefan; Sommer, Marco; Streit, Benjamin [Physikalisches Institut, Bonn (Germany)

    2015-07-01

    In order to improve the figure of merit of double-polarisation experiments at CB-ELSA in Bonn, the Polarised Target is working on a new dilution refrigerator. For maximum polarisation of nucleons low temperatures and a high homogeneous magnetic field within the target area is needed. A thin, superconducting magnet is in development, which will create a continuous longitudinal magnetic field of 2.5 T and which will be used within the new refrigerator. The solenoidal geometry of this magnet uses two additional correction coils, placed at a well defined calculated position, for reaching the homogeneity criteria of 10{sup -4} needed for the dynamic nuclear polarisation process. Practically, the superconducting wires as well as the correction coils have to be placed with maximum precision: Small fluctuations of the distance between the current loops can diminish the requested homogeneity.

  6. Polarisation effects in fibre lasers

    OpenAIRE

    Lin, J.T.; Morkel, P.R.; Reekie, L.; Payne, D.N.

    1987-01-01

    Two orthogonal polarisation eigenmodes have been observed in a single-mode fibre laser. Experimental investigation shows good agreement with theoretical analysis. Both Nd3+ and Er3+-doped single-polarisation single-mode fibre lasers have been demonstrated

  7. Vacuum field energy and spontaneous emission in anomalously dispersive cavities

    International Nuclear Information System (INIS)

    Bradshaw, Douglas H.; Di Rosa, Michael D.

    2011-01-01

    Anomalously dispersive cavities, particularly white-light cavities, may have larger bandwidth to finesse ratios than their normally dispersive counterparts. Partly for this reason, they have been proposed for use in laser interferometer gravitational-wave observatory (LIGO)-like gravity-wave detectors and in ring-laser gyroscopes. In this paper we analyze the quantum noise associated with anomalously dispersive cavity modes. The vacuum field energy associated with a particular cavity mode is proportional to the cavity-averaged group velocity of that mode. For anomalously dispersive cavities with group index values between 1 and 0, this means that the total vacuum field energy associated with a particular cavity mode must exceed (ℎ/2π)ω/2. For white-light cavities in particular, the group index approaches zero and the vacuum field energy of a particular spatial mode may be significantly enhanced. We predict enhanced spontaneous emission rates into anomalously dispersive cavity modes and broadened laser linewidths when the linewidth of intracavity emitters is broader than the cavity linewidth.

  8. POLARISATION PRESERVING OPTICAL FIBRE

    DEFF Research Database (Denmark)

    2000-01-01

    . This cladding structure provides polarisation preserving properties to the optical fibre. Optical fibres using this technology may have claddings with elements placed non-periodically as well as in a two-dimensional periodic lattice - such as cladding providing Photonic Band Gap (PBG) effects....

  9. Radiography with polarised neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, Michael L.

    2010-08-20

    In this thesis I present a new technique for the spatially resolved investigation of the magnetic properties of bulk samples. Standard one dimensional neutron depolarisation analysis is combined with neutron radiography to a method we call Neutron Depolarisation Imaging (NDI). The experimental setup which was installed at the neutron radiography beam line ANTARES at FRM II consists of a double crystal monochromator, neutron polariser, spin flipper, polarisation analyser and a position sensitive CCD detector. A comprehensive discussion of the requirements for these components is given and the limitations of the method are shown. The maximum spatial resolution which can be achieved with a neutron radiography setup is determined by the collimation of the neutron beam and the distance between sample and detector. Different types of polarisers have been tested and their advantages and disadvantages are discussed. A double crystal monochromator and a new type of polariser employing polarising neutron supermirrors based on the principle of an optical periscope were developed and tested during this work. Furthermore, NDI measurements on various samples of the weakly ferromagnetic materials Pd{sub 1-x}Ni{sub x} and Ni{sub 3}Al are presented. Neutron depolarisation radiography and tomography measurements were conducted with a spatial resolution as high as 0.3 mm on Pd{sub 1-x}Ni{sub x} and Ni{sub 3}Al samples. The feasibility of NDI experiments under hydrostatic pressures up to 10 kbar was shown on a sample of Ni{sub 3}Al using a modified Cu:Be clamp cell. A decrease of the ordering temperature by 2 K under hydrostatic pressure was determined from the NDI measurements and shows the potential of the method for further high pressure experiments. Additionally a method was developed which in principle allows to obtain the intrinsic dependence of the ordering temperature T{sub C} on the ordered moment Ms from NDI measurements on inhomogeneous samples containing regions with

  10. Radiography with polarised neutrons

    International Nuclear Information System (INIS)

    Schulz, Michael L.

    2010-01-01

    In this thesis I present a new technique for the spatially resolved investigation of the magnetic properties of bulk samples. Standard one dimensional neutron depolarisation analysis is combined with neutron radiography to a method we call Neutron Depolarisation Imaging (NDI). The experimental setup which was installed at the neutron radiography beam line ANTARES at FRM II consists of a double crystal monochromator, neutron polariser, spin flipper, polarisation analyser and a position sensitive CCD detector. A comprehensive discussion of the requirements for these components is given and the limitations of the method are shown. The maximum spatial resolution which can be achieved with a neutron radiography setup is determined by the collimation of the neutron beam and the distance between sample and detector. Different types of polarisers have been tested and their advantages and disadvantages are discussed. A double crystal monochromator and a new type of polariser employing polarising neutron supermirrors based on the principle of an optical periscope were developed and tested during this work. Furthermore, NDI measurements on various samples of the weakly ferromagnetic materials Pd 1-x Ni x and Ni 3 Al are presented. Neutron depolarisation radiography and tomography measurements were conducted with a spatial resolution as high as 0.3 mm on Pd 1-x Ni x and Ni 3 Al samples. The feasibility of NDI experiments under hydrostatic pressures up to 10 kbar was shown on a sample of Ni 3 Al using a modified Cu:Be clamp cell. A decrease of the ordering temperature by 2 K under hydrostatic pressure was determined from the NDI measurements and shows the potential of the method for further high pressure experiments. Additionally a method was developed which in principle allows to obtain the intrinsic dependence of the ordering temperature T C on the ordered moment Ms from NDI measurements on inhomogeneous samples containing regions with different ordering temperatures. This

  11. Polarisation analysis on the LET time-of-flight spectrometer

    Science.gov (United States)

    Nilsen, G. J.; Košata, J.; Devonport, M.; Galsworthy, P.; Bewley, R. I.; Voneshen, D. J.; Dalgliesh, R.; Stewart, J. R.

    2017-06-01

    We present a design for implementing uniaxial polarisation analysis on the LET cold neutron time-of-flight spectrometer, installed on the second target station at ISIS. The polarised neutron beam is to be produced by a transmission-based supermirror polariser with the polarising mirrors arranged in a “double-V” formation. This will be followed by a Mezei-type precession coil spin flipper, selected for its small spatial requirements, as well as a permanent magnet guide field to transport the beam polarisation to the sample position. The sample area will contain a set of holding field coils, whose purpose is to produce a highly homogenous magnetic field for the wide-angle 3He analyser cell. To facilitate fast cell changes and reduce the risk of cell failure, we intend to separate the cell and cryostat from the vacuum of the sample tank by installing both in a vessel at atmospheric pressure. When the instrument upgrade is complete, the performance of LET is expected to be commensurate with existing and planned polarised cold neutron spectrometers at other sources. Finally, we discuss the implications of performing uniaxial polarisation analysis only, and identify quasi-elastic neutron scattering (QENS) on ionic conducting materials as an interesting area to apply the technique.

  12. Development of a thin, internal superconducting polarisation magnet for the polarised target

    Energy Technology Data Exchange (ETDEWEB)

    Bornstein, Marcel; Dutz, Hartmut; Goertz, Stefan; Reeve, Scott; Runkel, Stefan [Physikalisches Institut, Bonn Univ. (Germany)

    2016-07-01

    In order to improve the figure of merit of double-polarisation experiments at CB-ELSA in Bonn, the Polarised Target is working on a new dilution refrigerator. For maximum polarisation of nucleons low temperatures and a high homogeneous magnetic field within the target area is needed. A thin, superconducting magnet is in development, which will create a continuous longitudinal magnetic field of 2.5 T and which will be used within the new refrigerator. The solenoidal geometry of this magnet uses two additional correction coils, placed at a well defined calculated position, for reaching the homogeneity criteria of 10{sup -4} needed for the dynamic nuclear process. Practically, the superconducting wires as well as the correction coils have to be placed with maximum precision: Small fluctuations of the distance between the current loops can diminish the requested homogeneity. A second build prototype passes first tests and looks promising to fulfil the particular requirements.

  13. Polarised neutron diffraction studies on weak ferromagnetism - a survey

    International Nuclear Information System (INIS)

    Radhakrishna, P.

    1982-10-01

    The physical basis of the phenomenon of weak ferromagnetism in certain antiferromagnetic insulators is briefly discussed. A survey of the contributions of polarised neutron diffraction towards the elucidation of different aspects of this field is presented

  14. Single top polarisation as a window to new physics

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Saavedra, J.A., E-mail: jaas@ugr.es [Departamento de Física Teórica y del Cosmos, Universidad de Granada, E-18071 Granada (Spain); Degrande, C. [CERN, Theory Department, Geneva 23 CH-1211 (Switzerland); Khatibi, S. [School of Particles and Accelerators, Institute for Research in Fundamental Sciences (IPM), P.O. Box 19395-5531, Tehran (Iran, Islamic Republic of)

    2017-06-10

    We discuss the effect of heavy new physics, parameterised in terms of four-fermion operators, in the polarisation of single top (anti-)quarks in the t-channel process at the LHC. It is found that for operators involving a right-handed top quark field the relative effect on the longitudinal polarisation is twice larger than the relative effect on the total cross section. This enhanced dependence on possible four-fermion contributions makes the polarisation measurements specially interesting, in particular at high momenta.

  15. Hadron Contribution to Vacuum Polarisation

    CERN Document Server

    Davier, M; Malaescu, B; Zhang, Z

    2016-01-01

    Precision tests of the Standard Theory require theoretical predictions taking into account higher-order quantum corrections. Among these vacuum polarisation plays a predominant role. Vacuum polarisation originates from creation and annihilation of virtual particle–antiparticle states. Leptonic vacuum polarisation can be computed from quantum electrodynamics. Hadronic vacuum polarisation cannot because of the non-perturbative nature of QCD at low energy. The problem is remedied by establishing dispersion relations involving experimental data on the cross section for e+ e− annihilation into hadrons. This chapter sets the theoretical and experimental scene and reviews the progress achieved in the last decades thanks to more precise and complete data sets. Among the various applications of hadronic vacuum polarisation calculations, two are emphasised: the contribution to the anomalous magnetic moment of the muon, and the running of the fine structure constant α to the Z mass scale. They are fundamental ingre...

  16. Optically induced dynamic nuclear spin polarisation in diamond

    International Nuclear Information System (INIS)

    Scheuer, Jochen; Naydenov, Boris; Jelezko, Fedor; Schwartz, Ilai; Chen, Qiong; Plenio, Martin B; Schulze-Sünninghausen, David; Luy, Burkhard; Carl, Patrick; Höfer, Peter; Retzker, Alexander; Sumiya, Hitoshi; Isoya, Junichi

    2016-01-01

    The sensitivity of magnetic resonance imaging (MRI) depends strongly on nuclear spin polarisation and, motivated by this observation, dynamical nuclear spin polarisation has recently been applied to enhance MRI protocols (Kurhanewicz et al 2011 Neoplasia 13 81). Nuclear spins associated with the 13 C carbon isotope (nuclear spin I = 1/2) in diamond possess uniquely long spin lattice relaxation times (Reynhardt and High 2011 Prog. Nucl. Magn. Reson. Spectrosc. 38 37). If they are present in diamond nanocrystals, especially when strongly polarised, they form a promising contrast agent for MRI. Current schemes for achieving nuclear polarisation, however, require cryogenic temperatures. Here we demonstrate an efficient scheme that realises optically induced 13 C nuclear spin hyperpolarisation in diamond at room temperature and low ambient magnetic field. Optical pumping of a nitrogen-vacancy centre creates a continuously renewable electron spin polarisation which can be transferred to surrounding 13 C nuclear spins. Importantly for future applications we also realise polarisation protocols that are robust against an unknown misalignment between magnetic field and crystal axis. (paper)

  17. Influence of local field on spontaneous light emission by nanoparticles

    DEFF Research Database (Denmark)

    Keller, Ole; Lozovski, V.; Iezhokin, I.

    2009-01-01

    moment of transition that takes local-field effects into account. The effective dipole moment depends on the particle shape and size. Therefore, dipole radiation depends on those parameters too. The direction patterns of light emission by cubic particles have been calculated. The particles have been......A self-consistent approach based on the local-field concept has been proposed to calculate the direction patterns of light emission by nanoparticles with various shapes. The main idea of the method consists in constructing self-consistent equations for the electromagnetic field at any point...... of the system. The solution of the equations brings about relationships between the local field at an arbitrary point in the system and the external long-wave field via the local-field factor. The latter connects the initial moment of optical dipole transition per system volume unit and the effective dipole...

  18. Theory of a metrology for the earths magnetic field based on the resonance of polarised atomic nuclei (1962); Theorie d'une metrologie du champ magnetique terrestre basee sur la resonance de noyaux atomiques polarises (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Bonnet, G [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1961-06-15

    The problems presented by the metrology of the earths field are studied from two points of view. a. The first, purely physical, concerns the study of NMR transducers in their role for the transformation of the magnetic field into a frequency. The possibilities and limitations are outlined. The use of an equivalent model is introduced systematically in the considerations of NMR phenomena, this makes it possible to treat all problems of interaction between a spin system and an electric detection system in a unified form. b. The other point of view concerns the restitution of the nuclear signal frequency in the form of a directly perceptible observable. The treatment of information is considered from a statistical angle, which leads to the study of an optimisation process concerning the linearization of the measurement as well as the minimisation of noise effects. (author) [French] Les problemes que pose la metrologie du champ terrestre sont etudies sous un double aspect: a. L'un, purement physique, concerne l'etude des traducteurs a RMN dans leur role de transformation du champ magnetique en une frequence. On en degage les possibilites et les limitations. L'emploi d'un modele equivalent est introduit de maniere systematique pour rendre compte des phenomenes de RMN, ce qui permet de traiter sous forme unifiee tous les problemes d'interaction entre un systeme de spins et un systeme electrique de detection. b. L'autre aspect concerne la restitution de la frequence du signal nucleaire sous la forme d'une observable directement perceptible. On considere le traitement de l'information sous l'aspect statistique, ce qui amene a etudier un processus d'optimisation concernant la linearisation de la mesure aussi bien que la minimisation des effets des bruits. (auteur)

  19. PANTHER - Polarisation Analysis with Thermal neutron

    International Nuclear Information System (INIS)

    Deen, P.P.; Fennell, T.; Schober, H.; Orecchini, A.; Rols, S.; Andersen, K.H.; Stewart, J.R.

    2011-01-01

    PANTHER will build on the success of IN4, the world's most intense time-of-flight spectrometer. A large position-sensitive detector (PSD) will improve data collection rates significantly, the background will be greatly reduced, and it will incorporate features indispensable for magnetic studies (small angles, polarisation analysis, high magnetic field devices). The new instrument will enable rapid surveys of (Q,ω) space, as well as more detailed studies in fields ranging from magnetism to the structural excitations - phonon densities of states, dispersion of collective modes and molecular vibrations - that govern the behaviour of many important physical and chemical systems. (authors)

  20. Particle-in-cell simulations on spontaneous thermal magnetic field fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Simões, F. J. R. Jr.; Pavan, J. [Instituto de Física e Matemática, UFPel, Pelotas, RS (Brazil); Gaelzer, R.; Ziebell, L. F. [Instituto de Física, UFRGS, Porto Alegre, RS (Brazil); Yoon, P. H. [Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742 (United States)

    2013-10-15

    In this paper an electromagnetic particle code is used to investigate the spontaneous thermal emission. Specifically we perform particle-in-cell simulations employing a non-relativistic isotropic Maxwellian particle distribution to show that thermal fluctuations are related to the origin of spontaneous magnetic field fluctuation. These thermal fluctuations can become seed for further amplification mechanisms and thus be considered at the origin of the cosmological magnetic field, at microgauss levels. Our numerical results are in accordance with theoretical results presented in the literature.

  1. Gluon Polarisation Measurements at COMPASS

    CERN Document Server

    Silva, Luís

    2012-01-01

    One of the missing keys in the present understanding of the spin structure of the nucleon is the contribution from the gluons: the so-called gluon polarisation. This quantity can be determined in DIS through the photon-gluon fusion process, in which two analysis methods may be used: (i) identifying open charm events or (ii) selecting events with high $p_{T}$ hadrons. The data used in the present work were collected in the COMPASS experiment, where a 160 GeV/c naturally polarised muon beam, impinging on a polarised nucleon fixed target is used. Preliminary results for the gluon polarisation from high $p_{T}$ and open charm analyses are presented. The gluon polarisation result for high $p_{T}$ hadrons is divided, for the first time, into three statistically independent measurements at LO. The result from open charm analysis is obtained at LO and NLO. In both analyses a new weighted method based on a neural network approach is used.

  2. Segregation of Spontaneous and Training Induced Recovery from Visual Field Defects in Subacute Stroke Patients

    Directory of Open Access Journals (Sweden)

    Douwe P. Bergsma

    2017-12-01

    Full Text Available Whether rehabilitation after stroke profits from an early start is difficult to establish as the contributions of spontaneous recovery and treatment are difficult to tease apart. Here, we use a novel training design to dissociate these components for visual rehabilitation of subacute stroke patients with visual field defects such as hemianopia. Visual discrimination training was started within 6 weeks after stroke in 17 patients. Spontaneous and training-induced recoveries were distinguished by training one-half of the defect for 8 weeks, while monitoring spontaneous recovery in the other (control half of the defect. Next, trained and control regions were swapped, and training continued for another 8 weeks. The same paradigm was also applied to seven chronic patients for whom spontaneous recovery can be excluded and changes in the control half of the defect point to a spillover effect of training. In both groups, field stability was assessed during a no-intervention period. Defect reduction was significantly greater in the trained part of the defect than in the simultaneously untrained part of the defect irrespective of training onset (p = 0.001. In subacute patients, training contributed about twice as much to their defect reduction as the spontaneous recovery. Goal Attainment Scores were significantly and positively correlated with the total defect reduction (p = 0.01, percentage increase reading speed was significantly and positively correlated with the defect reduction induced by training (epoch 1: p = 0.0044; epoch 2: p = 0.023. Visual training adds significantly to the spontaneous recovery of visual field defects, both during training in the early and the chronic stroke phase. However, field recovery as a result of training in this subacute phase was as large as in the chronic phase. This suggests that patients benefited primarily of early onset training by gaining access to a larger visual field sooner.

  3. Polarisation in the auroral red line during coordinated EISCAT Svalbard Radar/optical experiments

    Directory of Open Access Journals (Sweden)

    M. Barthélémy

    2011-06-01

    Full Text Available The polarisation of the atomic oxygen red line in the Earth's thermosphere is observed in different configurations with respect to the magnetic field line at high latitude during several coordinated Incoherent Scatter radar/optical experiment campaigns. When pointing northward with a line-of-sight nearly perpendicular to the magnetic field, we show that, as expected, the polarisation is due to precipitated electrons with characteristic energies of a few hundreds of electron Volts. When pointing toward the zenith or southward with a line-of-sight more parallel to the magnetic field, we show that the polarisation practically disappears. This confirms experimentally the predictions deduced from the recent discovery of the red line polarisation. We show that the polarisation direction is parallel to the magnetic field line during geomagnetic activity intensification and that these results are in agreement with theoretical work.

  4. Spontaneous membrane formation and self-encapsulation of active rods in an inhomogeneous motility field

    NARCIS (Netherlands)

    Grauer, J.; Löwen, H.; Janssen, L.M.C.

    2018-01-01

    We study the collective dynamics of self-propelled rods in an inhomogeneous motility field. At the interface between two regions of constant but different motility, a smectic rod layer is spontaneously created through aligning interactions between the active rods, reminiscent of an artificial,

  5. Chemical segregation and self polarisation in ferroelectrics

    Directory of Open Access Journals (Sweden)

    Bernard E. Watts

    2009-06-01

    Full Text Available Chemical partitioning or segregation is commonly encountered in solid-state syntheses. It is driven by compositional, thermal and electric field gradients. These phenomena can be quite extreme in thin films and lead to notable effects on the electrical properties of ferroelectrics. The segregation in ferroelectric thin films will be illustrated and the mechanisms explained in terms of diffusion processes driven by a potential gradient of the oxygen. The hypothesis can also explain self polarisation and imprint in ferroelectric hysteresis.

  6. Polarisation control of DFB fibre lasers

    DEFF Research Database (Denmark)

    Varming, Poul; Philipsen, Jacob Lundgreen; Berendt, Martin Ole

    1998-01-01

    The polarisation properties of a distributed feedback (DFB) fibre laser are investigated. It is shown experimentally that the birefringence of the UV induced phase-shift is the dominating effect controlling the polarisation properties of the laser......The polarisation properties of a distributed feedback (DFB) fibre laser are investigated. It is shown experimentally that the birefringence of the UV induced phase-shift is the dominating effect controlling the polarisation properties of the laser...

  7. Spontaneous symmetry breaking in local gauge quantum field theory; the Higgs mechanism

    International Nuclear Information System (INIS)

    Strocchi, F.

    1977-01-01

    Spontaneous symmetry breakings in indefinite metric quantum field theories are analyzed and a generalization of the Goldstone theorem is proved. The case of local gauge quantum field theories is discussed in detail and a characterization is given of the occurrence of the Higgs mechanism versus the Goldstone mechanism. The Higgs phenomenon is explained on general grounds without the introduction of the so-called Higgs fields. The basic property is the relation between the local internal symmetry group and the local group of gauge transformations of the second kind. Spontaneous symmetry breaking of c-number gauge transformations of the second kind is shown to always occur if there are charged local fields. The implications about the absence of mass gap in the Wightman functions and the occurrence of massless particles associated with the unbroken generators in the Higgs phenomenon are discussed. (orig.) [de

  8. The Interference of Polarised Light

    Indian Academy of Sciences (India)

    IAS Admin

    the optics of crystals with C V Raman at the Raman Research. Institute (RRI) in ... trate this contribution by means of specific examples, which ... applied to astronomy. The role ... The study of the effect of polarisation states of the two beams on.

  9. The commensurate spin excitation in chromium: A polarised neutron investigation

    International Nuclear Information System (INIS)

    Pynn, R.; Stirling, W.G.

    1991-01-01

    A polarised neutron experiment with neutron energy analysis has been performed with a single-Q sample of chromium in a large magnetic field. The 4-meV ''commensurate'' mode is found to involve spin fluctuations parallel to the ordered chromium moments. 8 refs., 3 figs

  10. Dynamic polarisation of nuclei

    International Nuclear Information System (INIS)

    Borghini, M.; Abragam, A.

    1961-01-01

    In magnetic fields of about 13000 gauss, at a temperature of 1.5 deg. K, in samples of about 2 mm 3 , we have obtained by the 'solid effect' (application of a magnetic field at an appropriate frequency around 35000 MHz), nuclear polarizations /I of a few percent: 19 per cent for hydrogen nuclei in single crystals of La 2 Mg 3 (NO 3 ) 12 , 24H 2 O; 5 per cent for hydrogen nuclei in polystyrene; 6 per cent for fluorine nuclei in single crystals of LiF. (author) [fr

  11. Interferometry with polarised neutrons

    International Nuclear Information System (INIS)

    Badurek, G.

    1978-01-01

    This paper aimed to give an outline of what might be expected from an extension of polarized beam techniques in neutron interferometry and how it could be achieved properly and what is the present state of this special field of interferometry

  12. The impact of chemical structure and molecular packing on the electronic polarisation of fullerene arrays.

    Science.gov (United States)

    Few, Sheridan; Chia, Cleaven; Teo, Daniel; Kirkpatrick, James; Nelson, Jenny

    2017-07-19

    Electronic polarisation contributes to the electronic landscape as seen by separating charges in organic materials. The nature of electronic polarisation depends on the polarisability, density, and arrangement of polarisable molecules. In this paper, we introduce a microscopic, coarse-grained model in which we treat each molecule as a polarisable site, and use an array of such polarisable dipoles to calculate the electric field and associated energy of any arrangement of charges in the medium. The model incorporates chemical structure via the molecular polarisability and molecular packing patterns via the structure of the array. We use this model to calculate energies of charge pairs undergoing separation in finite fullerene lattices of different chemical and crystal structures. The effective dielectric constants that we estimate from this approach are in good quantitative agreement with those measured experimentally in C 60 and phenyl-C 61 -butyric acid methyl ester (PCBM) films, but we find significant differences in dielectric constant depending on packing and on direction of separation, which we rationalise in terms of density of polarisable fullerene cages in regions of high field. In general, we find lattices containing molecules of more isotropic polarisability tensors exhibit higher dielectric constants. By exploring several model systems we conclude that differences in molecular polarisability (and therefore, chemical structure) appear to be less important than differences in molecular packing and separation direction in determining the energetic landscape for charge separation. We note that the results are relevant for finite lattices, but not necessarily for infinite systems. We propose that the model could be used to design molecular systems for effective electronic screening.

  13. Spontaneous scalarization with an extremely massive field and heavy neutron stars

    Science.gov (United States)

    Morisaki, Soichiro; Suyama, Teruaki

    2017-10-01

    We investigate the internal structure and the mass-radius relation of neutron stars in a recently proposed scalar-tensor theory dubbed asymmetron in which a massive scalar field undergoes spontaneous scalarization inside neutron stars. We focus on the case where the Compton wavelength is shorter than 10 km, which has not been investigated in the literature. By solving the modified Einstein equations, either purely numerically or by partially using a semianalytic method, we find that not only the weakening of gravity by spontaneous scalarization but also the scalar force affect the internal structure significantly in the massive case. We also find that the maximum mass of neutron stars is larger for certain parameter sets than that in general relativity and reaches 2 M⊙ even if the effect of strange hadrons is taken into account. There is even a range of parameters where the maximum mass of neutron stars largely exceeds the threshold that violates the causality bound in general relativity.

  14. Spin Polarisabilities and Compton Scattering from χEFT: Bridging QCD and Data

    Science.gov (United States)

    Griesshammer, Harald W.; McGovern, Judith A.; Phillips, Daniel R.

    2017-01-01

    Compton scattering from protons and neutrons probes their two-photon response in electric and magnetic fields of real photons, exploring the symmetries and interaction strengths of the internal degrees of freedom. With the scalar polarisabilities αE 1 and βM 1 now reasonably understood, the focus turns to the so-far poorly explored spin-polarisabilities. They parametrise the stiffness of the nucleon spin in external electro-magnetic fields, analogous to rotations of the polarisation of light by optically active media (bi-refringence/Faraday effect) and are particularly sensitive to the directional dependence of the πNγ interactions dictated by chiral symmetry and its breaking. This contribution addresses the potential of Chiral Effective Field Theory to relate between lattice QCD and ongoing or approved efforts at MAX-lab, HI γS and MAMI. We discuss high-intensity experiments with polarised targets and polarised beams which will allow the extraction of the spin-polarisabilities; χEFT predictions which indicate which observables for polarised protons, deuterons and 3 He are particularly sensitive; convergence, residual theoretical uncertainties and possibilities for improvement; and chiral extrapolations in mπ for lattice computations. Supported in part by UK STFC, US DOE and George Washington University.

  15. Neutron scattering from polarised proton domains

    CERN Document Server

    Van den Brandt, B; Kohbrecher, J; Konter, J A; Mango, S; Glattli, H; Leymarie, E; Grillo, I; May, R P; Jouve, H; Stuhrmann, H B; Stuhrmann, H B; Zimmer, O

    2002-01-01

    Time-dependent small-angle polarised neutron scattering from domains of polarised protons has been observed at the onset of dynamic nuclear polarisation in a frozen solution of 98% deuterated glycerol-water at 1 K containing a small concentration of paramagnetic centres (EHBA-Cr sup V). Simultaneous NMR measurements show that the observed scattering arises from protons around the Cr sup V -ions which are polarised to approx 10% in a few seconds, much faster than the protons in the bulk. (authors)

  16. Spontaneous symmetry breaking and the Goldstone theorem in non-Hermitian field theories arXiv

    CERN Document Server

    Alexandre, Jean; Millington, Peter; Seynaeve, Dries

    We demonstrate the extension to PT-symmetric field theories of the Goldstone theorem, confirming that the spontaneous appearance of a field vacuum expectation value via minimisation of the effective potential in a non-Hermitian model is accompanied by a massless scalar boson. Laying a basis for our analysis, we first show how the conventional quantisation of the path-integral formulation of quantum field theory can be extended consistently to a non-Hermitian model by considering PT conjugation instead of Hermitian conjugation. The extension of the Goldstone theorem to a PT-symmetric field theory is made possible by the existence of a conserved current that does not, however, correspond to a symmetry of the non-Hermitian Lagrangian. In addition to extending the proof of the Goldstone theorem to a PT-symmetric theory, we exhibit a specific example in which we verify the existence of a massless boson at the tree and one-loop levels.

  17. Inclusion in a Polarised World

    OpenAIRE

    Freeman, Alan

    2005-01-01

    This paper on inclusion was presented to the at the 2005 summer school of DEEEP (Development Education Exchange in Europe Project), Härnösand - Sweden, 5 - 12 June 2005. It addresses the significance of the concept of world civilisation. It assesses how meaning may be attached to the concept of inclusion in an economically polarised world. It develops a critique of the conception of economic inclusion, by means of an exploration of linguistic inclusion and the notion of ‘disability’. ‘...

  18. Spontaneous quasi single helicity regimes in EXTRAP T2R reversed-field pinch

    Science.gov (United States)

    Frassinetti, L.; Brunsell, P. R.; Drake, J. R.; Menmuir, S.; Cecconello, M.

    2007-11-01

    In recent years, good progress toward a better understanding and control of the plasma performance in reversed-field pinch devices has been made. These improvements consist both of the discovery of spontaneous plasma regimes, termed the quasi single helicity (QSH) regime, in which part of the plasma core is no longer stochastic, and of the development of techniques for active control of plasma instabilities. In this paper, a systematic study of spontaneous QSH in the EXTRAP T2R device [P. R. Brunsell, H. Bergsaker, M. Cecconello et al., Plasma Phys. Control. Fusion 43, 1457 (2001)] is presented. In this device, QSH states can occur spontaneously and it is associated with magnetic and thermal structures. A statistical analysis to determine the most favorable experimental conditions to have a transition to the QSH regime will be presented. The results described here are useful to understand the underlying properties of QSH regimes in view of future applications of the QSH active control in EXTRAP T2R; they are also important to have a comparison with the QSH studied in other devices.

  19. String dynamics, spontaneous breaking of supersymmetry, and dual scalar field theory

    International Nuclear Information System (INIS)

    Liu Luxin

    2009-01-01

    The dynamics of a vortex string, which describes the Nambu-Goldstone modes of the spontaneous breakdown of the target space D=4, N=1 supersymmetry and internal U(1) R symmetry to the world sheet ISO(1,1) symmetry, is constructed by using the approach of nonlinear realization. The resulting action describing the low energy oscillations of the string into the covolume (super)space is found to have an invariant synthesis form of the Akulov-Volkov and Nambu-Goto actions. Its dual scalar field action is obtained by means of introducing two vectorial Lagrangian multipliers into the action of the string.

  20. Charged tensor matter fields and Lorentz symmetry violation via spontaneous symmetry breaking

    International Nuclear Information System (INIS)

    Colatto, L.P.; Penna, A.L.A.; Santos, W.C.

    2003-10-01

    We consider a model with a charged vector field along with a Cremmer-Scherk-Kalb-Ramond (CSKR) matter field coupled to a U(1) gauge potential. We obtain a natural Lorentz symmetry violation due to the local U(1) spontaneous symmetry breaking mechanism triggered by the imaginary part of the vector matter. The choice of the unitary gauge leads to the decoupling of the gauge-Kr sector from the Higgs-Kr sector. The excitation spectrum is carefully analyzed and the physical modes are identified. We propose an identification of the neutral massive spin-1 Higgs-like field with the massive Z' boson of the so-called mirror matter models. (author)

  1. Control of spontaneous emission from a microwave-field-driven four-level atom in an anisotropic photonic crystal

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Duo, E-mail: zhangduo10@gmail.com [Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); School of Electrical and Electronic Engineering, Wuhan Polytechnic University, Wuhan 430023 (China); Li, Jiahua, E-mail: huajia_li@163.com [Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China); Ding, Chunling; Yang, Xiaoxue [Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2012-05-21

    The spontaneous emission properties of a microwave-field-driven four-level atom embedded in anisotropic double-band photonic crystals (PCs) are investigated. We discuss the influences of the band-edge positions, Rabi frequency and detuning of the microwave field on the emission spectrum. It is found that several interesting features such as spectral-line enhancement, spectral-line suppression, spectral-line overlap, and multi-peak structures can be observed in the spectra. The proposed scheme can be achieved by use of a microwave-coupled field into hyperfine levels in rubidium atom confined in a photonic crystal. These theoretical investigations may provide more degrees of freedom to manipulate the atomic spontaneous emission. -- Highlights: ► Spontaneous emission properties of an atom embedded in PCs are investigated. ► Spectral-line enhancement, suppression and overlapping are observed. ► The results provide more degrees of freedom to control atomic spontaneous emission.

  2. Control of spontaneous emission from a microwave-field-driven four-level atom in an anisotropic photonic crystal

    International Nuclear Information System (INIS)

    Zhang, Duo; Li, Jiahua; Ding, Chunling; Yang, Xiaoxue

    2012-01-01

    The spontaneous emission properties of a microwave-field-driven four-level atom embedded in anisotropic double-band photonic crystals (PCs) are investigated. We discuss the influences of the band-edge positions, Rabi frequency and detuning of the microwave field on the emission spectrum. It is found that several interesting features such as spectral-line enhancement, spectral-line suppression, spectral-line overlap, and multi-peak structures can be observed in the spectra. The proposed scheme can be achieved by use of a microwave-coupled field into hyperfine levels in rubidium atom confined in a photonic crystal. These theoretical investigations may provide more degrees of freedom to manipulate the atomic spontaneous emission. -- Highlights: ► Spontaneous emission properties of an atom embedded in PCs are investigated. ► Spectral-line enhancement, suppression and overlapping are observed. ► The results provide more degrees of freedom to control atomic spontaneous emission.

  3. On the electromagnetic polarisabilities of the nucleon

    International Nuclear Information System (INIS)

    Harun ar Rashid, A.M.

    1982-10-01

    The dynamic electric and magnetic polarisabilities of the nucleon are calculated taking the photon-nucleon resonance vertex-function ambiguity parameters into account. The annihilation channel in the Compton scattering amplitude is also evaluated from the chiral effective Lagrangian. It is found that the electric and magnetic polarisabilities of the proton are of the same order of magnitude. (author)

  4. Resolving dispersion and induction components for polarisable molecular simulations of ionic liquids

    Science.gov (United States)

    Pádua, Agílio A. H.

    2017-05-01

    One important development in interaction potential models, or atomistic force fields, for molecular simulation is the inclusion of explicit polarisation, which represents the induction effects of charged or polar molecules on polarisable electron clouds. Polarisation can be included through fluctuating charges, induced multipoles, or Drude dipoles. This work uses Drude dipoles and is focused on room-temperature ionic liquids, for which fixed-charge models predict too slow dynamics. The aim of this study is to devise a strategy to adapt existing non-polarisable force fields upon addition of polarisation, because induction was already contained to an extent, implicitly, due to parametrisation against empirical data. Therefore, a fraction of the van der Waals interaction energy should be subtracted so that the Lennard-Jones terms only account for dispersion and the Drude dipoles for induction. Symmetry-adapted perturbation theory is used to resolve the dispersion and induction terms in dimers and to calculate scaling factors to reduce the Lennard-Jones terms from the non-polarisable model. Simply adding Drude dipoles to an existing fixed-charge model already improves the prediction of transport properties, increasing diffusion coefficients, and lowering the viscosity. Scaling down the Lennard-Jones terms leads to still faster dynamics and densities that match experiment extremely well. The concept developed here improves the overall prediction of density and transport properties and can be adapted to other models and systems. In terms of microscopic structure of the ionic liquids, the inclusion of polarisation and the down-scaling of Lennard-Jones terms affect only slightly the ordering of the first shell of counterions, leading to small decreases in coordination numbers. Remarkably, the effect of polarisation is major beyond first neighbours, significantly weakening spatial correlations, a structural effect that is certainly related to the faster dynamics of

  5. The polarised Λ production in QCD

    International Nuclear Information System (INIS)

    Ravindran, V.

    1997-01-01

    The Q 2 evolution of polarised parton fragmentation functions is discussed using the Altarelli-Parisi evolution equations. The first moments of both the polarised quark and gluon fragmentation functions are shown to behave in a similar fashion at very high energies. This analysis is applicable to any hard processes involving the production of polarised hadrons. The polarised Λ hyperon production in e + e - annihilation where this can be realised is considered. We present complete α s (Q 2 ) corrections to the asymmetries discussed in the paper of Burkardt and Jaffe which demonstrates the extraction of various polarised fragmentation functions. To this order, these corrections are found to be scheme dependent similar to that of structure functions. (orig.)

  6. Polarisation of auroral emission lines in the Earth's upper atmosphere : first results and perspectives

    Science.gov (United States)

    Lamy, H.; Barthelemy, M.; Simon Wedlund, C.; Lilensten, J.; Bommier, V.

    2011-12-01

    Polarisation of light is a key observable to provide information about asymmetry or anisotropy within a radiative source. Following the pioneering and controversial work of Duncan in 1959, the polarisation of auroral emission lines in the Earth's upper atmosphere has been overlooked for a long time, even though the red intense auroral line (6300Å) produced by collisional impacts with electrons precipitating along magnetic field lines is a good candidate to search for polarisation. This problem was investigated again by Lilensten et al (2006) and observations were obtained by Lilensten et al (2008) confirming that the red auroral emission line is polarised. More recent measurements obtained by Barthélemy et al (2011) are presented and discussed. The results are compared to predictions of the theoretical work of Bommier et al (2011) and are in good agreement. Following these encouraging results, a new dedicated spectropolarimeter is currently under construction between BIRA-IASB and IPAG to provide simultaneously the polarisation of the red line and of other interesting auroral emission lines such as N2+ 1NG (4278Å), other N2 bands, etc... Perspectives regarding the theoretical polarisation of some of these lines will be presented. The importance of these polarisation measurements in the framework of atmospheric modeling and geomagnetic activity will be discussed.

  7. Magnetically aligned dust and SiO maser polarisation in the envelope of the red supergiant VY Canis Majoris

    Science.gov (United States)

    Vlemmings, W. H. T.; Khouri, T.; Martí-Vidal, I.; Tafoya, D.; Baudry, A.; Etoka, S.; Humphreys, E. M. L.; Jones, T. J.; Kemball, A.; O'Gorman, E.; Pérez-Sánchez, A. F.; Richards, A. M. S.

    2017-07-01

    Aims: Polarisation observations of circumstellar dust and molecular (thermal and maser) lines provide unique information about dust properties and magnetic fields in circumstellar envelopes of evolved stars. Methods: We use Atacama Large Millimeter/submillimeter Array (ALMA) Band 5 science verification observations of the red supergiant VY CMa to study the polarisation of SiO thermal/maser lines and dust continuum at 1.7 mm wavelength. We analyse both linear and circular polarisation and derive the magnetic field strength and structure, assuming the polarisation of the lines originates from the Zeeman effect, and that of the dust originates from aligned dust grains. We also discuss other effects that could give rise to the observed polarisation. Results: We detect, for the first time, significant polarisation ( 3%) of the circumstellar dust emission at millimeter wavelengths. The polarisation is uniform with an electric vector position angle of 8°. Varying levels of linear polarisation are detected for the J = 4 - 328SiO v = 0, 1, 2, and 29SiO v = 0, 1 lines, with the strongest polarisation fraction of 30% found for the 29SiO v = 1 maser. The linear polarisation vectors rotate with velocity, consistent with earlier observations. We also find significant (up to 1%) circular polarisation in several lines, consistent with previous measurements. We conclude that the detection is robust against calibration and regular instrumental errors, although we cannot yet fully rule out non-standard instrumental effects. Conclusions: Emission from magnetically aligned grains is the most likely origin of the observed continuum polarisation. This implies that the dust is embedded in a magnetic field >13 mG. The maser line polarisation traces the magnetic field structure. The magnetic field in the gas and dust is consistent with an approximately toroidal field configuration, but only higher angular resolution observations will be able to reveal more detailed field structure. If the

  8. Spontaneous and Widespread Electricity Generation in Natural Deep-Sea Hydrothermal Fields.

    Science.gov (United States)

    Yamamoto, Masahiro; Nakamura, Ryuhei; Kasaya, Takafumi; Kumagai, Hidenori; Suzuki, Katsuhiko; Takai, Ken

    2017-05-15

    Deep-sea hydrothermal vents discharge abundant reductive energy into oxidative seawater. Herein, we demonstrated that in situ measurements of redox potentials on the surfaces of active hydrothermal mineral deposits were more negative than the surrounding seawater potential, driving electrical current generation. We also demonstrated that negative potentials in the surface of minerals were widespread in the hydrothermal fields, regardless of the proximity to hydrothermal fluid discharges. Lab experiments verified that the negative potential of the mineral surface was induced by a distant electron transfer from the hydrothermal fluid through the metallic and catalytic properties of minerals. These results indicate that electric current is spontaneously and widely generated in natural mineral deposits in deep-sea hydrothermal fields. Our discovery provides important insights into the microbial communities that are supported by extracellular electron transfer and the prebiotic chemical and metabolic evolution of the ocean hydrothermal systems. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Renormalization of the scalar field theory with spontaneously broken discrete symmetry without shifting the field vacuum expectation value

    International Nuclear Information System (INIS)

    Solin, J.

    1988-01-01

    The one-loop renormalization of the λφ 4 theory with a spontaneous breaking of its discrete (reflection) symmetry is analyzed. It is explicitly shown that it is not necessary to forcefully eliminate the linear counterterm in the shifted field (accomplished usually by shifting the vacuum expectation value of the field) in order to have the renormalized Lagrangian still formally invariant under the original discrete symmetry. It is further shown, using the normal-ordering procedure, that the renormalization carried out in the customary form completely wipes out the tadpole diagram contributions from the original Lagrangian. As a consequence, the same renormalized Lagrangian can be also obtained from the original bare Lagrangian which, however, has been normal-ordered and as such cannot cause the linear counterterm in the shifted field since now the tadpole diagrams are absent altogether. These analyses should support the view that the vacuum expectation value of the field is of a group-theoretical origin rather than a field-theoretical origin, and as such should not change independently of the shifted field in the course of renormalization

  10. Space-time resolved measurements of spontaneous magnetic fields in laser-produced plasma

    Czech Academy of Sciences Publication Activity Database

    Pisarczyk, T.; Gus’kov, S.Yu.; Dudžák, Roman; Chodukowski, T.; Dostál, Jan; Demchenko, N. N.; Korneev, Ph.; Kalinowska, Z.; Kalal, M.; Renner, Oldřich; Šmíd, Michal; Borodziuk, S.; Krouský, Eduard; Ullschmied, Jiří; Hřebíček, Jan; Medřík, Tomáš; Golasowski, Jiří; Pfeifer, Miroslav; Skála, Jiří; Pisarczyk, P.

    2015-01-01

    Roč. 22, č. 10 (2015), č. článku 102706. ISSN 1070-664X R&D Projects: GA MŠk LM2010014; GA MŠk(CZ) LD14089; GA ČR GPP205/11/P712 Grant - others:FP7(XE) 284464 Program:FP7 Institutional support: RVO:61389021 ; RVO:68378271 Keywords : space-time resolved spontaneous magnetic field (SMF) * Laser System Subject RIV: BL - Plasma and Gas Discharge Physics; BL - Plasma and Gas Discharge Physics (FZU-D) OBOR OECD: Fluids and plasma physics (including surface physics); Fluids and plasma physics (including surface physics) (FZU-D) Impact factor: 2.207, year: 2015 http://scitation.aip.org/content/aip/journal/pop/22/10/10.1063/1.4933364

  11. Stabilization of Rayleigh-Taylor instability due to the spontaneous magnetic field in laser produced plasma

    International Nuclear Information System (INIS)

    Ogasawara, Masatada; Takita, Masami.

    1981-08-01

    Spontaneous magnetic fields due to the temperature gradient nabla T 0 produced by a focussed laser beam on one point of a pellet are taken into account in deriving the dispersion relation of Rayleigh-Taylor instability. Growth rate γ decreases with time. Density fluctuation with wavelength shorter than 1.5(R/L sub(T)) x (n sub(s)/n 0 )sup(1/2) μm is remarkably stabilized, where R, L sub(T), n sub(s) and n 0 are the radius of a pellet, L sub(T)sup(-1) = + nabla T 0 /T 0 + , number densities of solid and the pellet. Validity condition of the theory is γt 0 >> 1 or in another form R >> L, where t 0 is the time of thermal expansion of a pellet and L -1 = + nabla n 0 /n 0 + . (author)

  12. Effects of irradiation temperature on polarisation and relaxation characteristics of polymeric materials

    Energy Technology Data Exchange (ETDEWEB)

    Bornstein, Marcel; Dutz, Hartmut; Goertz, Stefan; Reeve, Scott; Runkel, Stefan [Physikalisches Institut, Bonn Univ. (Germany)

    2016-07-01

    To achieve significant enhancement of polarisation of solid target materials one must use the principles of dynamic nuclear polarisation and utilise the coupling of the nuclear and electron spins. The unpaired electrons needed can be created as paramagnetic structural defects by irradiation of the material. Polyethylene and polypropylene materials were irradiated at various temperatures and subsequently polarised with microwaves of approximately 70 GHz at temperatures around 1 K. Additionally the samples were investigated with respect to the nature of the created paramagnetic defects using a X-band EPR spectrometer. It was found that the irradiation temperature has a significant effect on the polarisation values achieved and also on the relaxation times of the materials in the 2.5 T magnetic field. The EPR line shape is clearly dominated by the well known alkyl radical structure.

  13. Spontaneous symmetry breaking, and strings defects in hypercomplex gauge field theories

    Energy Technology Data Exchange (ETDEWEB)

    Cartas-Fuentevilla, R. [Universidad Autonoma de Puebla, Instituto de Fisica, Puebla, Pue. (Mexico); Meza-Aldama, O. [Universidad Autonoma de Puebla, Facultad de Ciencias Fisico-Matematicas, Puebla, Pue. (Mexico)

    2016-02-15

    Inspired by the appearance of split-complex structures in the dimensional reduction of string theory, and in the theories emerging as byproducts, we study the hypercomplex formulation of Abelian gauge field theories by incorporating a new complex unit to the usual complex one. The hypercomplex version of the traditional Mexican hat potential associated with the U(1) gauge field theory, corresponds to a hybrid potential with two real components, and with U(1) x SO(1,1) as symmetry group. Each component corresponds to a deformation of the hat potential, with the appearance of a new degenerate vacuum. Hypercomplex electrodynamics will show novel properties, such as spontaneous symmetry breaking scenarios with running masses for the vectorial and scalar Higgs fields, and such as Aharonov-Bohm type strings defects as exact solutions; these topological defects may be detected only by quantum interference of charged particles through gauge invariant loop integrals. In a particular limit, the hyperbolic electrodynamics does not admit topological defects associated with continuous symmetries. (orig.)

  14. Field induced spontaneous quasiparticle decay and renormalization of quasiparticle dispersion in a quantum antiferromagnet.

    Science.gov (United States)

    Hong, Tao; Qiu, Y; Matsumoto, M; Tennant, D A; Coester, K; Schmidt, K P; Awwadi, F F; Turnbull, M M; Agrawal, H; Chernyshev, A L

    2017-05-05

    The notion of a quasiparticle, such as a phonon, a roton or a magnon, is used in modern condensed matter physics to describe an elementary collective excitation. The intrinsic zero-temperature magnon damping in quantum spin systems can be driven by the interaction of the one-magnon states and multi-magnon continuum. However, detailed experimental studies on this quantum many-body effect induced by an applied magnetic field are rare. Here we present a high-resolution neutron scattering study in high fields on an S=1/2 antiferromagnet C 9 H 18 N 2 CuBr 4 . Compared with the non-interacting linear spin-wave theory, our results demonstrate a variety of phenomena including field-induced renormalization of one-magnon dispersion, spontaneous magnon decay observed via intrinsic linewidth broadening, unusual non-Lorentzian two-peak structure in the excitation spectra and a dramatic shift of spectral weight from one-magnon state to the two-magnon continuum.

  15. Polarisation-sensitive optical elements in azobenzene polyesters and peptides

    DEFF Research Database (Denmark)

    Ramanujam, P.S.; Dam-Hansen, Carsten; Berg, Rolf Henrik

    2006-01-01

    In this article, we describe fabrication of polarisation holographic optical elements in azobenzene polyesters. Both liquid crystalline and amorphous side-chain polyesters have been utilised. Diffractive optical elements such as lenses and gratings that are sensitive to the polarisation...... of the incident light have been fabricated with polarisation holography. Computer-generated optical elements and patterns have also been written with a single polarised laser beam. Recording of polarisation defects enabling easy visualisation is also shown to be feasible in azobenzene polyesters....

  16. Polarised Black Holes in AdS

    CERN Document Server

    Costa, Miguel S.; Oliveira, Miguel; Penedones, João; Santos, Jorge E.

    2016-05-03

    We consider solutions in Einstein-Maxwell theory with a negative cosmological constant that asymptote to global $AdS_{4}$ with conformal boundary $S^{2}\\times\\mathbb{R}_{t}$. At the sphere at infinity we turn on a space-dependent electrostatic potential, which does not destroy the asymptotic $AdS$ behaviour. For simplicity we focus on the case of a dipolar electrostatic potential. We find two new geometries: (i) an $AdS$ soliton that includes the full backreaction of the electric field on the $AdS$ geometry; (ii) a polarised neutral black hole that is deformed by the electric field, accumulating opposite charges in each hemisphere. For both geometries we study boundary data such as the charge density and the stress tensor. For the black hole we also study the horizon charge density and area, and further verify a Smarr formula. Then we consider this system at finite temperature and compute the Gibbs free energy for both $AdS$ soliton and black hole phases. The corresponding phase diagram generalizes the Hawkin...

  17. The secret world of shrimps: polarisation vision at its best.

    Directory of Open Access Journals (Sweden)

    Sonja Kleinlogel

    Full Text Available BACKGROUND: Animal vision spans a great range of complexity, with systems evolving to detect variations in light intensity, distribution, colour, and polarisation. Polarisation vision systems studied to date detect one to four channels of linear polarisation, combining them in opponent pairs to provide intensity-independent operation. Circular polarisation vision has never been seen, and is widely believed to play no part in animal vision. METHODOLOGY/PRINCIPAL FINDINGS: Polarisation is fully measured via Stokes' parameters--obtained by combined linear and circular polarisation measurements. Optimal polarisation vision is the ability to see Stokes' parameters: here we show that the crustacean Gonodactylus smithii measures the exact components required. CONCLUSIONS/SIGNIFICANCE: This vision provides optimal contrast-enhancement and precise determination of polarisation with no confusion states or neutral points--significant advantages. Linear and circular polarisation each give partial information about the polarisation of light--but the combination of the two, as we will show here, results in optimal polarisation vision. We suggest that linear and circular polarisation vision not be regarded as different modalities, since both are necessary for optimal polarisation vision; their combination renders polarisation vision independent of strongly linearly or circularly polarised features in the animal's environment.

  18. Controlled and spontaneous magnetic field generation in a gun-driven spheromak

    International Nuclear Information System (INIS)

    Woodruff, S.; Cohen, B.I.; Hooper, E.B.; Mclean, H.S.; Stallard, B.W.; Hill, D.N.; Holcomb, C.T.; Romero-Talamas, C.; Wood, R.D.; Cone, G.; Sovinec, C.R.

    2005-01-01

    In the Sustained Spheromak Physics Experiment, SSPX [E. B. Hooper, D. Pearlstein, and D. D. Ryutov, Nucl. Fusion 39, 863 (1999)], progress has been made in understanding the mechanisms that generate fields by helicity injection. SSPX injects helicity (linked magnetic flux) from 1 m diameter magnetized coaxial electrodes into a flux-conserving confinement region. Control of magnetic fluctuations (δB/B∼1% on the midplane edge) yields T e profiles peaked at >200 eV. Trends indicate a limiting beta (β e ∼4%-6%), and so we have been motivated to increase T e by operating with stronger magnetic field. Two new operating modes are observed to increase the magnetic field: (A) Operation with constant current and spontaneous gun voltage fluctuations. In this case, the gun is operated continuously at the threshold for ejection of plasma from the gun: stored magnetic energy of the spheromak increases gradually with δB/B∼2% and large voltage fluctuations (δV∼1 kV), giving a 50% increase in current amplification, I tor /I gun . (B) Operation with controlled current pulses. In this case, spheromak magnetic energy increases in a stepwise fashion by pulsing the gun, giving the highest magnetic fields observed for SSPX (∼0.7 T along the geometric axis). By increasing the time between pulses, a quasisteady sustainment is produced (with periodic good confinement), comparing well with resistive magnetohydrodynamic simulations. In each case, the processes that transport the helicity into the spheromak are inductive and exhibit a scaling of field with current that exceeds those previously obtained. We use our newly found scaling to suggest how to achieve higher temperatures with a series of pulses

  19. Controlled and Spontaneous Magnetic Field Generation in a Gun-Driven Spheromak

    International Nuclear Information System (INIS)

    Woodruff, S; Cohen, B I; Hooper, E B; McLean, H S; Stallard, B W; Hill, D N; Holcomb, C T; Romero-Talamas, C; Wood, R D; Cone, G; Sovinec, C R

    2005-04-01

    In the Sustained Spheromak Physics Experiment, SSPX, progress has been made in understanding the mechanisms that generate fields by helicity injection. SSPX injects helicity (linked magnetic flux) from 1-m diameter magnetized coaxial electrodes into a flux-conserving confinement region. Control of magnetic fluctuations ((delta)B/B∼1% on the midplane edge) yields T e profiles peaked at > 200eV. Trends indicate a limiting beta (β e ∼ 4-6%), and so we have been motivated to increase T e by operating with stronger magnetic field. Two new operating modes are observed to increase the magnetic field: (A) Operation with constant current and spontaneous gun voltage fluctuations. In this case, the gun is operated continuously at the threshold for ejection of plasma from the gun: stored magnetic energy of the spheromak increases gradually with (delta)B/B ∼2% and large voltage fluctuations ((delta)V ∼ 1kV), giving a 50% increase in current amplification, I tor /I gun . (B) Operation with controlled current pulses. In this case, spheromak magnetic energy increases in a stepwise fashion by pulsing the gun, giving the highest magnetic fields observed for SSPX (∼0.7T along the geometric axis). By increasing the time between pulses, a quasi-steady sustainment is produced (with periodic good confinement), comparing well with resistive MHD simulations. In each case, the processes that transport the helicity into the spheromak are inductive and exhibit a scaling of field with current that exceeds those previously obtained. We use our newly found scaling to suggest how to achieve higher temperatures with a series of pulses

  20. Polarisation vision: overcoming challenges of working with a property of light we barely see

    Science.gov (United States)

    Foster, James J.; Temple, Shelby E.; How, Martin J.; Daly, Ilse M.; Sharkey, Camilla R.; Wilby, David; Roberts, Nicholas W.

    2018-04-01

    In recent years, the study of polarisation vision in animals has seen numerous breakthroughs, not just in terms of what is known about the function of this sensory ability, but also in the experimental methods by which polarisation can be controlled, presented and measured. Once thought to be limited to only a few animal species, polarisation sensitivity is now known to be widespread across many taxonomic groups, and advances in experimental techniques are, in part, responsible for these discoveries. Nevertheless, its study remains challenging, perhaps because of our own poor sensitivity to the polarisation of light, but equally as a result of the slow spread of new practices and methodological innovations within the field. In this review, we introduce the most important steps in designing and calibrating polarised stimuli, within the broader context of areas of current research and the applications of new techniques to key questions. Our aim is to provide a constructive guide to help researchers, particularly those with no background in the physics of polarisation, to design robust experiments that are free from confounding factors.

  1. Spontaneous symmetry breaking of (1+1)-dimensional φ4 theory in light-front field theory

    International Nuclear Information System (INIS)

    Bender, C.M.; Pinsky, S.; van de Sande, B.

    1993-01-01

    We study spontaneous symmetry breaking in (1+1)-dimensional φ 4 theory using the light-front formulation of field theory. Since the physical vacuum is always the same as the perturbative vacuum in light-front field theory the fields must develop a vacuum expectation value through the zero-mode components of the field. We solve the nonlinear operator equation for the zero mode in the one-mode approximation. We find that spontaneous symmetry breaking occurs at λ critical =4π(3+ √3 )μ 2 , which is consistent with the value λ critical =54.27μ 2 obtained in the equal-time theory. We calculate the vacuum expectation value as a function of the coupling constant in the broken phase both numerically and analytically using the δ expansion. We find two equivalent broken phases. Finally we show that the energy levels of the system have the expected behavior for the broken phase

  2. Higgs vacuum stability and inflationary dynamics after BICEP2 and PLANCK dust polarisation data

    International Nuclear Information System (INIS)

    Bhattacharya, Kaushik; Chakrabortty, Joydeep; Das, Suratna; Mondal, Tanmoy

    2014-01-01

    If the recent detection of B-mode polarization of the Cosmic Microwave Background by BICEP2 observations, withstand the test of time after the release of recent PLANCK dust polarisation data, then it would surprisingly put the inflationary scale near Grand Unification scale if one considers single-field inflationary models. On the other hand, Large Hadron Collider has observed the elusive Higgs particle whose presently observed mass can lead to electroweak vacuum instability at high scale (∼ O(10 10 ) GeV). In this article, we seek for a simple particle physics model which can simultaneously keep the vacuum of the theory stable and yield high-scale inflation successfully. To serve our purpose, we extend the Standard Model of particle physics with a U(1) B-L gauged symmetry which spontaneously breaks down just above the inflationary scale. Such a scenario provides a constrained parameter space where both the issues of vacuum stability and high-scale inflation can be successfully accommodated. The threshold effect on the Higgs quartic coupling due to the presence of the heavy inflaton field plays an important role in keeping the electroweak vacuum stable. Furthermore, this scenario is also capable of reheating the universe at the end of inflation. Though the issues of Dark Matter and Dark Energy, which dominate the late-time evolution of our universe, cannot be addressed within this framework, this model successfully describes the early universe dynamics according to the Big Bang model

  3. Spontaneous generation and reversals of mean flows in a convectively-generated internal gravity wave field

    Science.gov (United States)

    Couston, Louis-Alexandre; Lecoanet, Daniel; Favier, Benjamin; Le Bars, Michael

    2017-11-01

    We investigate via direct numerical simulations the spontaneous generation and reversals of mean zonal flows in a stably-stratified fluid layer lying above a turbulent convective fluid. Contrary to the leading idealized theories of mean flow generation by self-interacting internal waves, the emergence of a mean flow in a convectively-generated internal gravity wave field is not always possible because nonlinear interactions of waves of different frequencies can disrupt the mean flow generation mechanism. Strong mean flows thus emerge when the divergence of the Reynolds stress resulting from the nonlinear interactions of internal waves produces a strong enough anti-diffusive acceleration for the mean flow, which, as we will demonstrate, is the case when the Prandtl number is sufficiently low, or when the energy input into the internal wavefield by the convection and density stratification are sufficiently large. Implications for mean zonal flow production as observed in the equatorial stratospheres of the Earth, Saturn and Jupiter, and possibly occurring in other geophysical systems such as planetary and stellar interiors will be briefly discussed. Funding provided by the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program through Grant Agreement No. 681835-FLUDYCO-ERC-2015-CoG.

  4. Control of spontaneous emission from a microwave-field-driven four-level atom in an anisotropic photonic crystal

    Science.gov (United States)

    Zhang, Duo; Li, Jiahua; Ding, Chunling; Yang, Xiaoxue

    2012-05-01

    The spontaneous emission properties of a microwave-field-driven four-level atom embedded in anisotropic double-band photonic crystals (PCs) are investigated. We discuss the influences of the band-edge positions, Rabi frequency and detuning of the microwave field on the emission spectrum. It is found that several interesting features such as spectral-line enhancement, spectral-line suppression, spectral-line overlap, and multi-peak structures can be observed in the spectra. The proposed scheme can be achieved by use of a microwave-coupled field into hyperfine levels in rubidium atom confined in a photonic crystal. These theoretical investigations may provide more degrees of freedom to manipulate the atomic spontaneous emission.

  5. Renormalization of the Nambu-Jona Lasinio model and spontaneously broken Abelian Gauge model without fundamental scalar fields

    International Nuclear Information System (INIS)

    Snyderman, N.J.

    1976-01-01

    The Schwinger-Dyson equation for the Nambu-Jona Lasinio model is solved systematically subject to the constraint of spontaneously broken chiral symmetry. The solution to this equation generates interactions not explicitly present in the original Lagrangian, and the original 4-fermion interaction is not present in the solution. The theory creates bound-states with respect to which a perturbation theory consistent with the chiral symmetry is set up. The analysis suggests that this theory is renormalizable in the sense that all divergences can be grouped into a few arbitrary parameters. The renormalized propagators of this model are shown to be identical to those of a new solution to the sigma-model in which the bare 4-field coupling lambda 0 is chosen to be twice the π-fermion coupling g 0 . Also considered is spontaneously broken abelian gauge model without fundamental scalar fields by coupling an axial vector gauge field to the N ambu-Jona Lasinio model. It is shown how the Goldstone consequence of spontaneous symmetry breaking is avoided in the radiation gauge, and verify the Guralnik, Hagen, and Kibble theorem that under these conditions the global charge conservation is lost even though there is still local current conservation. This is contrasted with the Lorentz gauge situation. This also demonstrated the way the various noncovariant components of the massive gauge field combine in a gauge invariant scattering amplitude to propagate covariantly as a massive spin-1 particle, and this is compared with the Lorentz gauge calculation. F inally, a new model of interacting massless fermions is introduced, based on the models of Nambu and Jona Lasinio, and the Bjorken, which spontaneously breaks both chiral symmetry and Lorentz invariance. The content of this model is the same as that of the gauge model without fundamental scalar fields, but without fundamental gauge fields as well

  6. Measurement of W Polarisation at LEP

    CERN Document Server

    Achard, P; Aguilar-Benítez, M; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Anderhub, H; Andreev, V P; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Bajo, A; Baksay, G; Baksay, L; Baldew, S V; Banerjee, S; Barczyk, A; Barillère, R; Bartalini, P; Basile, M; Batalova, N; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Bellucci, L; Berbeco, R; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Biasini, M; Biglietti, M; Biland, A; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böhm, A; Boldizsar, L; Borgia, B; Bottai, S; Bourilkov, D; Bourquin, Maurice; Braccini, S; Branson, J G; Brochu, F; Burger, J D; Burger, W J; Cai, X D; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada, M; Chamizo-Llatas, M; Chang, Y H; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chiefari, G; Cifarelli, Luisa; Cindolo, F; Clare, I; Clare, R; Coignet, G; Colino, N; Costantini, S; de la Cruz, B; Cucciarelli, S; van Dalen, J A; De Asmundis, R; Déglon, P L; Debreczeni, J; Degré, A; Dehmelt, K; Deiters, K; Della Volpe, D; Delmeire, E; Denes, P; De Notaristefani, F; De Salvo, A; Diemoz, M; Dierckxsens, M; Dionisi, C; Dittmar, M; Doria, A; Dova, M T; Duchesneau, D; Duda, M; Echenard, B; Eline, A; El-Hage, A; El-Mamouni, H; Engler, A; Eppling, F J; Extermann, P; Falagán, M A; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, M; Ferguson, T; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisher, W; Fisk, I; Forconi, G; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gataullin, M; Gentile, S; Giagu, S; Gong, Z F; Grenier, G; Grimm, O; Grünewald, M W; Guida, M; van Gulik, R; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hakobyan, R S; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hirschfelder, J; Hofer, H; Hohlmann, M; Holzner, G; Hou, S R; Hu, Y; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Käfer, D; Kaur, M; Kienzle-Focacci, M N; Kim, J K; Kirkby, Jasper; Kittel, E W; Klimentov, A; König, A C; Kopal, M; Koutsenko, V F; Kräber, M H; Krämer, R W; Krüger, A; Kunin, A; Ladrón de Guevara, P; Laktineh, I; Landi, G; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Le Goff, J M; Leiste, R; Levtchenko, M; Levchenko, P M; Li, C; Likhoded, S; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lü, Y S; Luci, C; Luminari, L; Lustermann, W; Ma Wen Gan; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Mans, J; Martin, J P; Marzano, F; Mazumdar, K; McNeil, R R; Mele, S; Merola, L; Meschini, M; Metzger, W J; Mihul, A; Milcent, H; Mirabelli, G; Mnich, J; Mohanty, G B; Muanza, G S; Muijs, A J M; Musicar, B; Musy, M; Nagy, S; Natale, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Nisati, A; Nowak, H; Ofierzynski, R A; Organtini, G; Palomares, C; Paolucci, P; Paramatti, R; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Pedace, M; Pensotti, S; Perret-Gallix, D; Petersen, B; Piccolo, D; Pierella, F; Pioppi, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Pothier, J; Prokofiev, D O; Prokofev, D; Quartieri, J; Rahal-Callot, G; Rahaman, M A; Raics, P; Raja, N; Ramelli, R; Rancoita, P G; Ranieri, R; Raspereza, A V; Razis, P A; Ren, D; Rescigno, M; Reucroft, S; Riemann, S; Riles, K; Roe, B P; Romero, L; Rosca, A; Rosier-Lees, S; Roth, S; Rosenbleck, C; Roux, B; Rubio, J A; Ruggiero, G; Rykaczewski, H; Sakharov, A; Saremi, S; Sarkar, S; Salicio, J; Sánchez, E; Sanders, M P; Schäfer, C; Shchegelskii, V; Schopper, Herwig Franz; Schotanus, D J; Sciacca, C; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shumilov, E; Shvorob, A V; Son, D; Souga, C; Spillantini, P; Steuer, M; Stickland, D P; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Sushkov, S; Suter, H; Swain, J D; Szillási, Z; Tang, X W; Tarjan, P; Tauscher, Ludwig; Taylor, L; Tellili, B; Teyssier, D; Timmermans, C; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tung, K L; Ulbricht, J; Valente, E; Van de Walle, R T; Vásquez, R; Veszpremi, V; Vesztergombi, G; Vetlitskii, I; Vicinanza, D; Viertel, Gert M; Villa, S; Vivargent, M; Vlachos, S; Vodopyanov, I; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Wadhwa, M; Wang, X L; Wang, Z M; Weber, M; Wienemann, P; Wilkens, H; Wynhoff, S; Xia, L; Xu, Z Z; Yamamoto, J; Yang, B Z; Yang, C G; Yang, H J; Yang, M; Yeh, S C; Zalite, A; Zalite, Yu; Zhang, Z P; Zhao, J; Zhu, G Y; Zhu, R Y; Zhuang, H L; Zichichi, A; Zimmermann, B; Zöller, M

    2003-01-01

    The three different helicity states of W bosons produced in the reaction e+ e- -> W+ W- -> l nu q q~ at LEP are studied using leptonic and hadronic W decays. Data at centre-of-mass energies \\sqrt s = 183-209 GeV are used to measure the polarisation of W bosons, and its dependence on the W boson production angle. The fraction of longitudinally polarised W bosons is measured to be 0.218 \\pm 0.027 \\pm 0.016 where the first uncertainty is statistical and the second systematic, in agreement with the Standard Model expectation.

  7. Towards high resolution polarisation analysis using double polarisation and ellipsoidal analysers

    CERN Document Server

    Martin-Y-Marero, D

    2002-01-01

    Classical polarisation analysis methods lack the combination of high resolution and high count rate necessary to cope with the demand of modern condensed-matter experiments. In this work, we present a method to achieve high resolution polarisation analysis based on a double polarisation system. Coupling this method with an ellipsoidal wavelength analyser, a high count rate can be achieved whilst delivering a resolution of around 10 mu eV. This method is ideally suited to pulsed sources, although it can be adapted to continuous sources as well. (orig.)

  8. Depolarisation effects in resonance absorption neutron polarising filters

    International Nuclear Information System (INIS)

    Mayers, J.

    1982-06-01

    The depolarisation of a neutron beam passing through a system of magnetically misaligned single domain particles is examined and simulated using a Monte-Carlo programme. The results of the simulations are in excellent agreement with those of analytic calculations within the regimes where such calculations are applicable. The simulations have been used in the estimation of the polarising efficiency and transmittance of a resonance absorption filter containing partially aligned particles of SmCo 5 . It is shown that the application of strong magnetic fields (approximately equal to 2T) should significantly improve the filter performance. A method of measuring this improvement is suggested. (author)

  9. Spontaneous emission from active dielectric microstructures

    DEFF Research Database (Denmark)

    Søndergaard, Thomas; Tromborg, Bjarne

    2001-01-01

    and engineered due to the dependence of the emission rate on the location and polarisation of the emitters in the structure. This paper addresses the methods of quantum electrodynamics of dielectric media which enable calculation of the local rate of spontaneous emission in active microstructures....

  10. Light-front quantized field theory (an introduction): spontaneous symmetry breaking. Phase transition in φ4 theory

    International Nuclear Information System (INIS)

    Srivastava, Prem P.

    1994-01-01

    The Dirac procedure is used to construct the Hamiltonian formulation of the scalar field theory on the light-front. The theory is quantized and the mechanism of the spontaneous symmetry breaking in the front form and the instant form dynamics are compared. The phase transition in (φ 4 )2 theory is also discussed and found to be of the second order. (author). 36 refs

  11. Unbiased Polarised Parton Distribution Functions and their Uncertainties

    CERN Document Server

    Nocera, Emanuele R.; Ridolfi, Giovanni; Rojo, Juan

    2012-01-01

    We present preliminary results on the determination of spin-dependent, or polarised, Parton Distribution Functions (PDFs) from all relevant inclusive polarised DIS data. The analysis is performed within the NNPDF approach, which provides a faithful and statistically sound representation of PDFs and their uncertainties. We describe how the NNPDF methodology has been extended to the polarised case, and compare our results with other recent polarised parton sets. We show that polarised PDF uncertainties can be sizeably underestimated in standard determinations, most notably for the gluon.

  12. Polarisation of electroweak gauge bosons at the LHC

    Directory of Open Access Journals (Sweden)

    Vryonidou Eleni

    2013-05-01

    Full Text Available We present results for the polarisation of gauge bosons produced at the LHC. Polarisation effects for W bosons manifest themselves in the angular distributions of the lepton and in the distributions of lepton transverse momentum and missing transverse energy. The polarisation is discussed for a range of different processes producing W bosons such as W+jets and W from top production. The relative contributions of the different polarisation states vary from process to process, reflecting the dynamics of the underlying hardscattering process. We also calculate the polarisation of the Z boson produced in association with QCD jets at the LHC.

  13. In situ SEOP polarised {sup 3}He neutron spin filter for incident beam polarisation and polarisation analysis on neutron scattering instruments

    Energy Technology Data Exchange (ETDEWEB)

    Boag, S., E-mail: s.boag@rl.ac.u [ISIS, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX (United Kingdom); Babcock, E. [Institut Laue-langevin, 6 rue J. horowitz, BP 156, 38042, Grenoble Cedex 9 (France); Juelich Centre for Neutron Science at FRM II, Lichtenbergstrae 1, 85747 Garching (Germany); Andersen, K.H.; Becker, M. [Institut Laue-langevin, 6 rue J. horowitz, BP 156, 38042, Grenoble Cedex 9 (France); Charlton, T.R. [ISIS, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX (United Kingdom); Chen, W.C. [National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899 (United States); Dalgliesh, R.M.; Elmore, S.D.; Frost, C.D. [ISIS, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX (United Kingdom); Gentile, T.R. [National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899 (United States); Lopez Anton, R. [ISIS, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX (United Kingdom); ICMA, CSIC-Universidad de Zaragoza, Zaragoza 50009 (Spain); Parnell, S.R. [Academic Unit of Radiology, University of Sheffield, S10 2JF (United Kingdom); Petoukhov, A.K. [Institut Laue-langevin, 6 rue J. horowitz, BP 156, 38042, Grenoble Cedex 9 (France); Skoda, M.W.A. [ISIS, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX (United Kingdom); Soldner, T. [Institut Laue-langevin, 6 rue J. horowitz, BP 156, 38042, Grenoble Cedex 9 (France)

    2009-09-01

    We discuss the development and characterisation of a new in situ spin exchange optical pumping (SEOP) based {sup 3}He neutron spin filter polarisation device. We present results from a recent test of the prototype system developed with the Institut Laue-Langevin. The polariser was installed on the polarised reflectometer CRISP at ISIS in the analyser position. The {sup 3}He was pumped continuously in situ on the beamline. The system also integrated a {sup 3}He adiabatic fast passage spin flipper that allowed reversal of the {sup 3}He and therefore neutron polarisation state, allowing for measurement of all four polarisation cross-sections. The system was run for a number of days reaching a {sup 3}He polarisation of 63%.

  14. Proposed Spontaneous Generation of Magnetic Fields by Curved Layers of a Chiral Superconductor

    Science.gov (United States)

    Kvorning, T.; Hansson, T. H.; Quelle, A.; Smith, C. Morais

    2018-05-01

    We demonstrate that two-dimensional chiral superconductors on curved surfaces spontaneously develop magnetic flux. This geometric Meissner effect provides an unequivocal signature of chiral superconductivity, which could be observed in layered materials under stress. We also employ the effect to explain some puzzling questions related to the location of zero-energy Majorana modes.

  15. Ultracompact high-efficiency polarising beam splitter based on silicon nanobrick arrays.

    Science.gov (United States)

    Zheng, Guoxing; Liu, Guogen; Kenney, Mitchell Guy; Li, Zile; He, Ping'an; Li, Song; Ren, Zhi; Deng, Qiling

    2016-03-21

    Since the transmission of anisotropic nano-structures is sensitive to the polarisation of an incident beam, a novel polarising beam splitter (PBS) based on silicon nanobrick arrays is proposed. With careful design of such structures, an incident beam with polarisation direction aligned with the long axis of the nanobrick is almost totally reflected (~98.5%), whilst that along the short axis is nearly totally transmitted (~94.3%). More importantly, by simply changing the width of the nanobrick we can shift the peak response wavelength from 1460 nm to 1625 nm, covering S, C and L bands of the fiber telecommunications windows. The silicon nanobrick-based PBS can find applications in many fields which require ultracompactness, high efficiency, and compatibility with semiconductor industry technologies.

  16. Proton Radiography of Spontaneous Fields, Plasma Flows and Dynamics in X-Ray Driven Inertial-Confinement Fusion Implosions

    Science.gov (United States)

    Li, C. K.; Seguin, F. H.; Frenje, J. A.; Rosenberg, M.; Zylstra, A. B.; Rinderknecht, H. G.; Petrasso, R. D.; Amendt, P. A.; Landen, O. L.; Town, R. P. J.; Betti, R.; Knauer, J. P.; Meyerhofer, D. D.; Back, C. A.; Kilkenny, J. D.; Nikroo, A.

    2010-11-01

    Backlighting of x-ray-driven implosions in empty hohlraums with mono-energetic protons on the OMEGA laser facility has allowed a number of important phenomena to be observed. Several critical parameters were determined, including plasma flow, three types of spontaneous electric fields and megaGauss magnetic fields. These results provide insight into important issues in indirect-drive ICF. Even though the cavity is effectively a Faraday cage, the strong, local fields inside the hohlraum can affect laser-plasma instabilities, electron distributions and implosion symmetry. They are of fundamental scientific importance for a range of new experiments at the frontiers of high-energy-density physics. Future experiments designed to characterize the field formation and evolution in low-Z gas fill hohlraums will be discussed.

  17. W Boson Polarisation at LEP2

    CERN Document Server

    Abbiendi, G.; Akesson, P.F.; Alexander, G.; Allison, John; Amaral, P.; Anagnostou, G.; Anderson, K.J.; Arcelli, S.; Asai, S.; Axen, D.; Azuelos, G.; Bailey, I.; Barberio, E.; Barillari, T.; Barlow, R.J.; Batley, R.J.; Bechtle, P.; Behnke, T.; Bell, Kenneth Watson; Bell, P.J.; Bella, G.; Bellerive, A.; Benelli, G.; Bethke, S.; Biebel, O.; Boeriu, O.; Bock, P.; Boutemeur, M.; Braibant, S.; Brigliadori, L.; Brown, Robert M.; Buesser, K.; Burckhart, H.J.; Campana, S.; Carnegie, R.K.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, D.G.; Ciocca, C.; Couchman, J.; Csilling, A.; Cuffiani, M.; Dado, S.; De Roeck, A.; De Wolf, E.A.; Desch, K.; Dienes, B.; Donkers, M.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Etzion, E.; Fabbri, F.; Feld, L.; Ferrari, P.; Fiedler, F.; Fleck, I.; Ford, M.; Frey, A.; Gagnon, P.; Gary, John William; Gaycken, G.; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Giunta, Marina; Goldberg, J.; Gross, E.; Grunhaus, J.; Gruwe, M.; Gunther, P.O.; Gupta, A.; Hajdu, C.; Hamann, M.; Hanson, G.G.; Harel, A.; Hauschild, M.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Herten, G.; Heuer, R.D.; Hill, J.C.; Hoffman, Kara Dion; Horvath, D.; Igo-Kemenes, P.; Ishii, K.; Jeremie, H.; Jovanovic, P.; Junk, T.R.; Kanaya, N.; Kanzaki, J.; Karlen, D.; Kawagoe, K.; Kawamoto, T.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Klein, K.; Klier, A.; Kluth, S.; Kobayashi, T.; Kobel, M.; Komamiya, S.; Kramer, T.; Krieger, P.; von Krogh, J.; Kruger, K.; Kuhl, T.; Kupper, M.; Lafferty, G.D.; Landsman, H.; Lanske, D.; Layter, J.G.; Lellouch, D.; Lettso, J.; Levinson, L.; Lillich, J.; Lloyd, S.L.; Loebinger, F.K.; Lu, J.; Ludwig, A.; Ludwig, J.; Mader, W.; Marcellini, S.; Martin, A.J.; Masetti, G.; Mashimo, T.; Mattig, Peter; McKenna, J.; McPherson, R.A.; Meijers, F.; Menges, W.; Merritt, F.S.; Mes, H.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D.J.; Moed, S.; Mohr, W.; Mori, T.; Mutter, A.; Nagai, K.; Nakamura, I.; Nanjo, H.; Neal, H.A.; Nisius, R.; O'Neale, S.W.; Oh, A.; Okpara, A.; Oreglia, M.J.; Orito, S.; Pahl, C.; Pasztor, G.; Pater, J.R.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Poli, B.; Pooth, O.; Przybycien, M.; Quadt, A.; Rabbertz, K.; Rembser, C.; Renkel, P.; Roney, J.M.; Rosati, S.; Rozen, Y.; Runge, K.; Sachs, K.; Saeki, T.; Sarkisyan, E.K.G.; Schaile, A.D.; Schaile, O.; Scharff-Hansen, P.; Schieck, J.; Schoerner-Sadenius, Thomas; Schroder, Matthias; Schumacher, M.; Scott, W.G.; Seuster, R.; Shears, T.G.; Shen, B.C.; Sherwood, P.; Skuja, A.; Smith, A.M.; Sobie, R.; Soldner-Rembold, S.; Spano, F.; Stahl, A.; Strom, David M.; Strohmer, R.; Tarem, S.; Tasevsky, M.; Teuscher, R.; Thomson, M.A.; Torrence, E.; Toya, D.; Tran, P.; Trigger, I.; Trocsanyi, Z.; Tsur, E.; Turner-Watson, M.F.; Ueda, I.; Ujvari, B.; Vollmer, C.F.; Vannerem, P.; Vertesi, R.; Verzocchi, M.; Voss, H.; Vossebeld, J.; Waller, D.; Ward, C.P.; Ward, D.R.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wengler, T.; Wermes, N.; Wetterling, D.; Wilson, G.W.; Wilson, J.A.; Wolf, G.; Wyatt, T.R.; Yamashita, S.; Zer-Zion, D.; Zivkovic, Lidija

    2004-01-01

    Elements of the spin density matrix for W bosons in e+e- -> W+W- -> qqln events are measured from data recorded by the OPAL detector at LEP. This information is used calculate polarised differential cross-sections and to search for CP-violating effects. Results are presented for W bosons produced in e+e- collisions with centre-of-mass energies between 183 GeV and 209 GeV. The average fraction of W bosons that are longitudinally polarised is found to be (23.9 +- 2.1 +- 1.1)% compared to a Standard Model prediction of (23.9 +- 0.1)%. All results are consistent with CP conservation.

  18. Measurement of the Tau Polarisation at LEP

    CERN Document Server

    Heister, A.; Barate, R.; De Bonis, I.; Decamp, D.; Ghez, Philippe; Goy, C.; Lees, J.P.; Merle, E.; Minard, M.N.; Pietrzyk, B.; Alemany, R.; Bravo, S.; Casado, M.P.; Chmeissani, M.; Crespo, J.M.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, L.; Grauges, E.; Martinez, M.; Merino, G.; Miquel, R.; Mir, L.M.; Pacheco, A.; Ruiz, H.; Colaleo, A.; Creanza, D.; de Palma, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Tricomi, A.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Abbaneo, D.; Azzurri, P.; Boix, G.; Buchmuller, O.; Cattaneo, M.; Cerutti, F.; Clerbaux, B.; Dissertori, G.; Drevermann, H.; Forty, R.W.; Frank, M.; Greening, T.C.; Hansen, J.B.; Harvey, John; Janot, P.; Jost, B.; Kado, M.; Mato, P.; Moutoussi, A.; Ranjard, F.; Rolandi, Gigi; Schlatter, D.; Schmitt, M.; Schneider, O.; Spagnolo, P.; Tejessy, W.; Teubert, F.; Tournefier, E.; Ward, J.; Wright, A.E.; Ajaltouni, Z.; Badaud, F.; Falvard, A.; Gay, P.; Henrard, P.; Jousset, J.; Michel, B.; Monteil, S.; Montret, J.C.; Pallin, D.; Perret, P.; Podlyski, F.; Hansen, J.D.; Hansen, J.R.; Hansen, P.H.; Nilsson, B.S.; Waananen, A.; Daskalakis, G.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Vayaki, A.; Blondel, A.; Bonneaud, G.; Brient, J.C.; Rouge, A.; Rumpf, M.; Swynghedauw, M.; Verderi, M.; Videau, H.; Focardi, E.; Parrini, G.; Zachariadou, K.; Antonelli, A.; Antonelli, M.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Chiarella, V.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G.P.; Passalacqua, L.; Pepe-Altarelli, M.; Halley, A.W.; Lynch, J.G.; Negus, P.; O'Shea, V.; Raine, C.; Thompson, A.S.; Wasserbaech, S.; Cavanaugh, R.; Dhamotharan, S.; Geweniger, C.; Hanke, P.; Hansper, G.; Hepp, V.; Kluge, E.E.; Putzer, A.; Sommer, J.; Tittel, K.; Werner, S.; Wunsch, M.; Beuselinck, R.; Binnie, D.M.; Cameron, W.; Dornan, P.J.; Girone, M.; Marinelli, N.; Sedgbeer, J.K.; Thompson, J.C.; Ghete, V.M.; Girtler, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Bouhova-Thacker, E.; Bowdery, C.K.; Finch, A.J.; Foster, F.; Hughes, G.; Jones, R.W.L.; Pearson, M.R.; Robertson, N.A.; Giehl, I.; Jakobs, K.; Kleinknecht, K.; Quast, G.; Renk, B.; Rohne, E.; Sander, H.G.; Wachsmuth, H.; Zeintiz, C.; Bonissent, A.; Carr, J.; Coyle, P.; Leroy, O.; Payre, P.; Rousseau, D.; Talby, M.; Aleppo, M.; Ragusa, F.; David, A.; Dietl, H.; Ganis, G.; Huttmann, K.; Lutjens, G.; Mannert, C.; Manner, W.; Moser, H.G.; Settles, R.; Stenzel, H.; Wiedenmann, W.; Wolf, G.; Boucrot, J.; Callot, O.; Chen, S.; Davier, M.; Duflot, L.; Grivaz, J.F.; Heusse, P.; Jacholkowska, A.; Lefrancois, J.; Nikolic, Irina; Veillet, J.J.; Videau, I.; Yuan, C.; Bagliesi, Giuseppe; Boccali, T.; Calderini, G.; Ciulli, V.; Foa, L.; Giassi, A.; Ligabue, F.; Messineo, A.; Palla, F.; Sanguinetti, G.; Sciaba, A.; Sguazzoni, G.; Tenchini, R.; Venturi, A.; Verdini, P.G.; Blair, G.A.; Cowan, G.; Green, M.G.; Medcalf, T.; Strong, J.A.; Teixeira-Dias, P.; von Wimmersperg-Toeller, J.H.; Clifft, R.W.; Edgecock, T.R.; Norton, P.R.; Tomalin, I.R.; Bloch-Devaux, Brigitte; Colas, P.; Emery, S.; Kozanecki, W.; Lancon, E.; Lemaire, M.C.; Locci, E.; Perez, P.; Rander, J.; Renardy, J.F.; Roussarie, A.; Schuller, J.P.; Schwindling, J.; Trabelsi, A.; Vallage, B.; Konstantinidis, N.; Litke, A.M.; Taylor, G.; Booth, C.N.; Cartwright, S.; Combley, F.; Lehto, M.; Thompson, L.F.; Affholderbach, K.; Boehrer, Armin; Brandt, S.; Grupen, C.; Misiejuk, A.; Ngac, A.; Prange, G.; Sieler, U.; Giannini, G.; Rothberg, J.; Armstrong, S.R.; Cranmer, K.; Elmer, P.; Ferguson, D.P.S.; Gao, Y.; Gonzalez, S.; Hayes, O.J.; Hu, H.; Jin, S.; Kile, J.; McNamara, P.A., III; Nielsen, J.; Orejudos, W.; Pan, Y.B.; Saadi, Y.; Scott, I.J.; Walsh, J.; Wu, Sau Lan; Wu, X.; Zobernig, G.

    2001-01-01

    The polarisation of $\\tau$'s produced in Z decay is measured using 160 pb$^{-1}$ of data accumulated at LEP by the ALEPH detector between 1990 and 1995. The variation of the polarisation with polar angle yields the two parameters ${\\cal A}_e = 0.1504 \\pm 0.0068 $ and ${\\cal A}_{\\tau} = 0.1451 \\pm 0.0059$ which are consistent with the hypothesis of $e$-$\\tau$ universality. Assuming universality, the value ${\\cal A}_{e\\mbox{-}\\tau} = 0.1474 \\pm 0.0045$ is obtained from which the effective weak mixing angle $\\sin^2 {\\theta_{\\mathrm{W}}^{\\mathrm{eff}}} =0.23147 \\pm 0.00057 $ is derived.

  19. The renormalization group of relativistic quantum field theory as a set of generalized, spontaneously broken, symmetry transformations

    International Nuclear Information System (INIS)

    Maris, Th.A.J.

    1976-01-01

    The renormalization group theory has a natural place in a general framework of symmetries in quantum field theories. Seen in this way, a 'renormalization group' is a one-parametric subset of the direct product of dilatation and renormalization groups. This subset of spontaneously broken symmetry transformations connects the inequivalent solutions generated by a parameter-dependent regularization procedure, as occurs in renormalized perturbation theory. By considering the global, rather than the infinitesimal, transformations, an expression for general vertices is directly obtained, which is the formal solution of exact renormalization group equations [pt

  20. Internal electric fields due to piezoelectric and spontaneous polarizations in CdZnO/MgZnO quantum well with various applied electric field effects

    International Nuclear Information System (INIS)

    Jeon, H.C.; Lee, S.J.; Kang, T.W.; Park, S.H.

    2012-01-01

    The strain-induced piezoelectric polarization and the spontaneous polarization can be reduced effectively using the applied electric field in the CdZnO/ZnMgO quantum well (QW) structure with high Cd composition. That is, optical properties as a function of internal and external fields in the CdZnO/ZnMgO QW with various applied electric field result in the increased optical gain due to the fact that the QW potential profile is flattened as a result of the compensation of the internal field by the reverse field as confirmed. These results demonstrate that a high-performance optical device operation can be realized in CdZnO/MgZnO QW structures by reducing the droop phenomenon.

  1. Internal electric fields due to piezoelectric and spontaneous polarizations in CdZnO/MgZnO quantum well with various applied electric field effects

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, H.C. [Quantum-functional Semiconductor Research Center, Dongguk University, Seoul 100-715 (Korea, Republic of); Lee, S.J., E-mail: leesj@dongguk.edu [Quantum-functional Semiconductor Research Center, Dongguk University, Seoul 100-715 (Korea, Republic of); Kang, T.W. [Quantum-functional Semiconductor Research Center, Dongguk University, Seoul 100-715 (Korea, Republic of); Park, S.H. [Department of Electronics Engineering, Catholic University of Daegu, Kyeongbuk 712-702 (Korea, Republic of)

    2012-05-15

    The strain-induced piezoelectric polarization and the spontaneous polarization can be reduced effectively using the applied electric field in the CdZnO/ZnMgO quantum well (QW) structure with high Cd composition. That is, optical properties as a function of internal and external fields in the CdZnO/ZnMgO QW with various applied electric field result in the increased optical gain due to the fact that the QW potential profile is flattened as a result of the compensation of the internal field by the reverse field as confirmed. These results demonstrate that a high-performance optical device operation can be realized in CdZnO/MgZnO QW structures by reducing the droop phenomenon.

  2. How to polarise all neutrons in one beam: a high performance polariser and neutron transport system

    Science.gov (United States)

    Rodriguez, D. Martin; Bentley, P. M.; Pappas, C.

    2016-09-01

    Polarised neutron beams are used in disciplines as diverse as magnetism,soft matter or biology. However, most of these applications often suffer from low flux also because the existing neutron polarising methods imply the filtering of one of the spin states, with a transmission of 50% at maximum. With the purpose of using all neutrons that are usually discarded, we propose a system that splits them according to their polarisation, flips them to match the spin direction, and then focuses them at the sample. Monte Carlo (MC) simulations show that this is achievable over a wide wavelength range and with an outstanding performance at the price of a more divergent neutron beam at the sample position.

  3. Role of spontaneous emission through operating transition in probe-field spectroscopy of two-level systems

    Energy Technology Data Exchange (ETDEWEB)

    Saprykin, E. G. [Russian Academy of Sciences, Institute of Automation and Electrometry, Siberian Branch (Russian Federation); Chernenko, A. A., E-mail: chernen@isp.nsc.ru [Russian Academy of Sciences, Rzhanov Institute of Semiconductor Physics, Siberian Branch (Russian Federation); Shalagin, A. M. [Russian Academy of Sciences, Institute of Automation and Electrometry, Siberian Branch (Russian Federation)

    2016-08-15

    Analytical and numerical investigations are carried out of the effect of spontaneous decay through operating transition on the shape of a resonance in the work of a probe field under a strong field applied to the transition. A narrow nonlinear resonance arising on transitions with long-living lower level in the work of a probe field can manifest itself in the form of a traditional minimum and a peak as a function of the first Einstein coefficient for the operating transition. The transformation of the resonance from a minimum to a peak is attributed to the specific character of relaxation of lower-level population beatings on a closed or almost closed transition (the decay of the upper level occurs completely or almost completely through the operating transition).

  4. Linearly polarised photons at the BGO-OD experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bella, Andreas [Physikalisches Institut, Universitaet Bonn (Germany); Collaboration: BGO-OD-Collaboration

    2015-07-01

    The BGO-OD experiment, located at the ELSA accelerator of the University of Bonn, aims at the study of photoproduction reactions off the nucleon. A real, energy-tagged photon beam is produced via bremsstrahlung by irradiating a thin radiator with the electron beam provided by ELSA. Linear polarisation is obtained by coherent bremsstrahlung. This requires a crystal radiator; in our case a 570 μm thick diamond is used. The production mechanism of a linearly polarised photon beam via coherent bremsstrahlung, the determination of the degree of polarisation and first results obtained with a linearly polarised photon beam are shown in this talk.

  5. Spontaneous symmetry breaking of (1+1)-dimensional φ4 theory in light-front field theory. II

    International Nuclear Information System (INIS)

    Pinsky, S.S.; van de Sande, B.

    1994-01-01

    We discuss spontaneous symmetry breaking of (1+1)-dimensional φ 4 theory in light-front field theory using a Tamm-Dancoff truncation. We show that, even though light-front field theory has a simple vacuum state which is an eigenstate of the full Hamiltonian, the field can develop a nonzero vacuum expectation value. This occurs because the zero mode of the field must satisfy an operator-valued constraint equation. In the context of (1+1)-dimensional φ 4 theory we present solutions to the constraint equation using a Tamm-Dancoff truncation to a finite number of particles and modes. We study the behavior of the zero mode as a function of coupling and Fock space truncation. The zero mode introduces new interactions into the Hamiltonian which breaks the Z 2 symmetry of the theory when the coupling is stronger than the critical coupling. We investigate the energy spectrum in the symmetric and broken phases, show that the theory does not break down in the vicinity of the critical coupling, and discuss the connection to perturbation theory. Finally, we study the spectrum of the field φ and show that, in the broken phase, the field is localized away from φ=0 as one would expect from equal-time calculations. We explicitly show that tunneling occurs

  6. Measurement of the charged-pion polarisability at COMPASS

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    For more than a decade, COMPASS has been tackling the measurement of the electromagnetic polarizability of the charged pion, which describes the stiffness of the pion against deformation in electromagnetic fields. Previous experiments date back to the 1980's in Serpukhov (Russia), where the Primakoff method for realizing interactions of charged pions with quasi-real photons was first employed. Later also other techniques in photon-nucleon and photon-photon collisions were carried out at different machines. The COMPASS measurement demonstrates that the charged-pion polarizability is significantly smaller than the previous results, roughly by a factor two, with the smallest uncertainties realized so far. The pion polarisability is of fundamental interest in the low-energy sector of quantum chromodynamics. It is directly linked to the quark-gluon substructure and dynamics of the pion, the lightest bound system of strong interaction.

  7. Polarised Photon Beams for the BGO-OD Experiment at ELSA

    Science.gov (United States)

    Zimmermann, T.; Bella, A.; Alef, S.; Bayadilov, D.; Beck, R.; Becker, M.; Bielefeldt, P.; Boese, S.; Braghieri, A.; Brinkmann, K.; Cole, P.; Curciarello, F.; De Leo, V.; Di Salvo, R.; Dutz, H.; Elsner, D.; Fantini, A.; Freyermuth, O.; Friedrich, S.; Frommberger, F.; Ganenko, V.; Gervino, G.; Ghio, F.; Giardina, G.; Goertz, S.; Gridnev, A.; Gutz, E.; Hammann, D.; Hannappel, J.; Hartmann, P.; Hillert, W.; Ignatov, A.; Jahn, R.; Joosten, R.; Jude, T. C.; Klein, F.; Koop, K.; Krusche, B.; Lapik, A.; Levi Sandri, P.; Lopatin, I. V.; Mandaglio, G.; Messi, F.; Messi, R.; Metag, V.; Moricciani, D.; Mushkarenkov, A.; Nanova, M.; Nedorezov, V.; Novinskiy, D.; Pedroni, P.; Reitz, B.; Romaniuk, M.; Rostomyan, T.; Rudnev, N.; Schaerf, C.; Scheluchin, G.; Schmieden, H.; Stugelev, A.; Sumachev, V.; Tarakanov, V.; Vegna, V.; Walther, D.; Watts, D.; Zaunick, H.

    The new BGO-OD experiment at the electron accelerator ELSA, of the University of Bonn, is designed to study the reaction dynamics of nucleon excitations in meson photoproduction. It consists of a central BGO calorimeter with a magnetic spectrometer in forward direction. The physics programme includes the measurement of polarisation observables using linearly and circularly polarised photon beams. Linear polarisation is obtained by coherent bremsstrahlung off a diamond crystal, and circular polarisation is obtained via bremsstrahlung from longitudinally polarised electrons. The degree of linear polarisation is determined from the bremsstrahlung spectrum itself. To determine the polarisation of the circularly polarised photon beam, the polarisation of the electron beam is measured by a Møller polarimeter. As a preliminary consistency check, the (linear) polarisation observable, Σ, was compared to world data for π0 and η photoproduction. To determine the degree of circular polarisation, a Møller polarimeter was setup and first measurements of the electron beam polarisation performed.

  8. Cross-polarised and parallel-polarised light: Viewing and photography for examination and documentation of biological materials in medicine and forensics.

    Science.gov (United States)

    Hanlon, Katharine L

    2018-01-01

    Cross-polarisation, with regard to visible light, is a process wherein two polarisers with perpendicular orientation to one another are used on the incident and reflected lights. Under cross-polarised light birefringent structures which are otherwise invisible become apparent. Cross-polarised light eliminates glare and specular highlights, allowing for an unobstructed view of subsurface pathology. Parallel-polarisation occurs when the polarisers are rotated to the same orientation. When cross- or parallel-polarisation is applied to photography, images can be generated which aid in visualisation of surface and subsurface elements. Improved access to equipment and education has the potential to benefit practitioners, researchers, investigators and patients.

  9. Spin polarisation with electron Bessel beams

    Energy Technology Data Exchange (ETDEWEB)

    Schattschneider, P., E-mail: schattschneider@ifp.tuwien.ac.at [Institut für Festkörperphysik, Technische Universität Wien, A-1040 Wien (Austria); USTEM, Technische Universität Wien, A-1040 Wien (Austria); Grillo, V. [CNR-Istituto Nanoscienze, Centro S3, Via G Campi 213/a, I-41125 Modena (Italy); CNR-IMEM, Parco delle Scienze 37a, I-43100 Parma (Italy); Aubry, D. [Centrale Supelec, MSSMast CNRS 8579, F-92295 Châtenay-Malabry (France)

    2017-05-15

    The theoretical possibility to use an electron microscope as a spin polarizer is studied. It turns out that a Bessel beam passing a standard magnetic objective lens is intrinsically spin polarized when post-selected on-axis. In the limit of infinitely small detectors, the spin polarisation tends to 100 %. Increasing the detector size, the polarisation decreases rapidly, dropping below 10{sup −4} for standard settings of medium voltage microscopes. For extremely low voltages, the Figure of Merit increases by two orders of magnitude, approaching that of existing Mott detectors. Our findings may lead to new desings of spin filters, an attractive option in view of its inherent combination with the electron microscope, especially at low voltage. - Highlights: • TEM round magnetic lenses can act as spin polarizers when a Bessel beam is sent through. • This is found on theoretical grounds and demonstrated numerically for a few cases. • The effect is small, but can reach a Figure of Merit similar to existing Mott detectors. • This opens the possibility to construct nanometer-sized spin filters or detectors.

  10. Usage of polarisation features of landmines for improved automatic detection

    NARCIS (Netherlands)

    Jong, W. de; Cremer, F.; Schutte, K.; Storm, J.

    2000-01-01

    In this paper the landmine detection performance of an infrared and a visual light camera both equipped with a polarisation filter are compared with the detection performance of these cameras without polarisation filters. Sequences of images have been recorded with in front of these cameras a

  11. Sensitivity versus polarisation in multilayer optical thin film design

    Directory of Open Access Journals (Sweden)

    Efrem K. Ejigu

    2012-07-01

    Full Text Available The design of a polarised optical filter is more complicated than that of a filter where the polarisation effect does not exist (at a normal angle of incidence. An error in the optical parameters, such as the physical thickness or refractive index of a layer, results in a change in the spectral performance of the multilayer structure. The correlation between error sensitivity and the polarisation effect of light in structures designed at an oblique angle was investigated. To illustrate the correlation, a perpendicular (S and parallel (P polarised beam splitter, at 0.9818 µm central wavelength, designed by genetic algorithm, was used. The beam splitter changes its state of polarisation according to the error in thickness simultaneously induced in each of the layers. The error was calculated by optimising the original design. The observation of the change of the state of polarisation as a result of error sensitivity leads to a different method of designing pure S-polarised or P-polarised optical filters.

  12. Perimetric demonstration of spontaneous visual field recovery following occipital lobe haemorrhage.

    Science.gov (United States)

    Lin, Siying; George, Badie Z; Wilson-Holt, Nicholas J

    2013-08-29

    A 45-year-old patient on lifelong warfarin therapy after a metal aortic valve replacement developed a homonymous visual field defect following an occipital lobe haemorrhage. The patient received only conservative management and yet described continued improvement in her visual field defect for up to 20 months following the initial cerebral insult. We present the first conclusive illustrative documentation of visual recovery in a patient with an occipital lobe haemorrhage with sequential automated perimetric assessments over an extended period of time.

  13. Spherical domain wall formed by field dynamics of Hawking radiation and spontaneous charging-up of black hole

    International Nuclear Information System (INIS)

    Nagatani, Yukinori

    2004-01-01

    We investigate the Hawking radiation in the gauge Higgs-Yukawa theory. The ballistic model is proposed as an effective description of the system. We find that a spherical domain wall around the black hole is formed by field dynamics rather than thermal phase transition. The formation is a general property of the black hole whose Hawking temperature is equal to or greater than the energy scale of the theory. The formation of the electroweak wall and that of the GUT wall are shown. We also find a phenomenon of the spontaneous charging-up of the black hole by the wall. The Hawking radiation drives a mechanism of the charge transportation into the black hole when C- and CP-violation are assumed. The mechanism can strongly transport the hyper-charge into a black hole of the electroweak scale

  14. Proceedings of the second workshop on polarised target materials

    International Nuclear Information System (INIS)

    Court, G.R.; Niinikoski, T.O.; Cox, S.F.J.; Cragg, D.A.

    1980-10-01

    The proceedings are reported of a second international workshop which was convened to consider the use of polarised targets in nuclear research and in particular the experimental difficulties imposed by the limitations of target materials with respect to their relatively low hydrogen content and susceptibility to radiation damage. Papers presented were entitled: (1) Introduction and general review. (2) Theory of dynamic nuclear polarisation. (3) Radiation induced paramagnetic centres in organic and inorganic materials. (4) Dynamic nuclear polarisation with radiation induced free radicals. (5) Radiation damage of chemically doped materials. (6) Chemical doping. (7) Techniques and instrumentation. (8) The use of polarised nuclei in physics with neutrons. (9) The use of polarised targets in high energy physics. (U.K.)

  15. Spontaneously broken symmetry of vacuum in external gravitational fields of isotropic cosmological models

    International Nuclear Information System (INIS)

    Veryaskin, A.V.; Lapchinskij, V.G.; Nekrasov, V.I.; Rubakov, V.A.

    1981-01-01

    Behaviour of vacuum symmetry in the model of self-acting scalar field in the open and closed isotropic cosmological spaces is investigated. Considered are the cases with the mass squared of the scalar field m 2 >0, m 2 =0 and m 2 2 2 =0 at exponentially large scale factors the study of the problem on the behaviour of the symmetry requires exceeding the limits of the perturbation theory. The final behaviour of the vacuum symmetry in the open model at small radii depends on combined effect of all the external factors [ru

  16. Penetration depth of YBa2Cu3O7 measured by polarised neutron reflectometry

    International Nuclear Information System (INIS)

    Reynolds, J.M.; Nunez, V.; Boothroyd, A.T.; Bucknall, D.G.; Penfold, J.

    1998-01-01

    We have applied the technique of polarised neutron reflectometry (PNR) to investigate the magnetic field profile near the surface of YBa 2 Cu 3 O 7 films at 4.3 K. The samples comprised 700-1400 nm of c-axis oriented, single crystal YBa 2 Cu 3 O 7 deposited by laser ablation on SrTiO 3 substrates. The measurements were carried out on the CRISP reflectometer at the ISIS facility. The PNR technique measures the magnetic induction profile perpendicular to the surface, and so in our case the decay of flux in the c-direction was measured with a field applied parallel to the ab plane. We present preliminary data for the polarised and unpolarised reflectivity (orig.)

  17. Social Polarisation and the Danish Welfare State

    DEFF Research Database (Denmark)

    Christensen, Anders Bøggild; Rasmussen, Tove Valborg

    look at Aarhus in the light of these theories and studies of other cities. We present some preliminary results of a study based on public registered data covering income, capital, occupation, social services, types of dwellings, localisation etc. in the municipality of Aarhus. On the one hand we paint...... a preliminary picture of Aarhus looking at the distribution of poverty and wealth showing some indicators towards inequality. Furthermore we discuss central theories, concepts and measured indicators......Globalisation and the information society tend - according to leading theories - to increase social polarisation and create dual cities. Studies have shown that the tendencies are more complicated in several of the European cities and the welfare state seems to have an impact on the development. We...

  18. Measurement of $\\tau$ polarisation at LEP

    CERN Document Server

    Acciarri, M; Aguilar-Benítez, M; Ahlen, S P; Alcaraz, J; Alemanni, G; Allaby, James V; Aloisio, A; Alviggi, M G; Ambrosi, G; Anderhub, H; Andreev, V P; Angelescu, T; Anselmo, F; Arefev, A; Azemoon, T; Aziz, T; Bagnaia, P; Baksay, L; Ball, R C; Banerjee, S; Banerjee, Sw; Banicz, K; Barczyk, A; Barillère, R; Barone, L; Bartalini, P; Baschirotto, A; Basile, M; Battiston, R; Bay, A; Becattini, F; Becker, U; Behner, F; Berdugo, J; Berges, P; Bertucci, B; Betev, B L; Bhattacharya, S; Biasini, M; Biland, A; Bilei, G M; Blaising, J J; Blyth, S C; Bobbink, Gerjan J; Böck, R K; Böhm, A; Boldizsar, L; Borgia, B; Bourilkov, D; Bourquin, Maurice; Boutigny, D; Braccini, S; Branson, J G; Brigljevic, V; Brock, I C; Buffini, A; Buijs, A; Burger, J D; Burger, W J; Busenitz, J K; Cai, X D; Campanelli, M; Capell, M; Cara Romeo, G; Carlino, G; Cartacci, A M; Casaus, J; Castellini, G; Cavallari, F; Cavallo, N; Cecchi, C; Cerrada-Canales, M; Cesaroni, F; Chamizo-Llatas, M; Chang, Y H; Chaturvedi, U K; Chekanov, S V; Chemarin, M; Chen, A; Chen, G; Chen, G M; Chen, H F; Chen, H S; Chen, M; Chiefari, G; Chien, C Y; Cifarelli, Luisa; Cindolo, F; Civinini, C; Clare, I; Clare, R; Cohn, H O; Coignet, G; Colijn, A P; Colino, N; Costantini, S; Cotorobai, F; de la Cruz, B; Csilling, Akos; Dai, T S; D'Alessandro, R; De Asmundis, R; Degré, A; Deiters, K; Denes, P; De Notaristefani, F; DiBitonto, Daryl; Diemoz, M; Van Dierendonck, D N; Di Lodovico, F; Dionisi, C; Dittmar, Michael; Dominguez, A; Doria, A; Dova, M T; Drago, E; Duchesneau, D; Duinker, P; Durán, I; Dutta, S; Easo, S; Efremenko, Yu V; El-Mamouni, H; Engler, A; Eppling, F J; Erné, F C; Ernenwein, J P; Extermann, Pierre; Fabre, M; Faccini, R; Falciano, S; Favara, A; Fay, J; Fedin, O; Felcini, Marta; Fenyi, B; Ferguson, T; Ferroni, F; Fesefeldt, H S; Fiandrini, E; Field, J H; Filthaut, Frank; Fisher, P H; Fisk, I; Forconi, G; Fredj, L; Freudenreich, Klaus; Furetta, C; Galaktionov, Yu; Ganguli, S N; García-Abia, P; Gau, S S; Gentile, S; Gerald, J; Gheordanescu, N; Giagu, S; Goldfarb, S; Goldstein, J; Gong, Z F; Gougas, Andreas; Gratta, Giorgio; Grünewald, M W; Gupta, V K; Gurtu, A; Gutay, L J; Haas, D; Hartmann, B; Hasan, A; Hatzifotiadou, D; Hebbeker, T; Hervé, A; Hirschfelder, J; Van Hoek, W C; Hofer, H; Hoorani, H; Hou, S R; Hu, G; Innocente, Vincenzo; Jenkes, K; Jin, B N; Jones, L W; de Jong, P; Josa-Mutuberria, I; Kasser, A; Khan, R A; Kamrad, D; Kamyshkov, Yu A; Kapustinsky, J S; Karyotakis, Yu; Kaur, M; Kienzle-Focacci, M N; Kim, D; Kim, D H; Kim, J K; Kim, S C; Kinnison, W W; Kirkby, A; Kirkby, D; Kirkby, Jasper; Kiss, D; Kittel, E W; Klimentov, A; König, A C; Kopp, A; Korolko, I; Koutsenko, V F; Krämer, R W; Krenz, W; Kunin, A; Lacentre, P E; Ladrón de Guevara, P; Landi, G; Lapoint, C; Lassila-Perini, K M; Laurikainen, P; Lavorato, A; Lebeau, M; Lebedev, A; Lebrun, P; Lecomte, P; Lecoq, P; Le Coultre, P; Lee, H J; Leggett, C; Le Goff, J M; Leiste, R; Leonardi, E; Levchenko, P M; Li Chuan; Lin, C H; Lin, W T; Linde, Frank L; Lista, L; Liu, Z A; Lohmann, W; Longo, E; Lu, W; Lü, Y S; Lübelsmeyer, K; Luci, C; Luckey, D; Luminari, L; Lustermann, W; Ma Wen Gan; Maity, M; Majumder, G; Malgeri, L; Malinin, A; Maña, C; Mangeol, D J J; Mangla, S; Marchesini, P A; Marin, A; Martin, J P; Marzano, F; Massaro, G G G; McNally, D; Mele, S; Merola, L; Meschini, M; Metzger, W J; Von der Mey, M; Mi, Y; Migani, D; Mihul, A; Van Mil, A J W; Milcent, H; Mirabelli, G; Mnich, J; Molnár, P; Monteleoni, B; Moore, R; Moulik, T; Mount, R; Muheim, F; Muijs, A J M; Nahn, S; Napolitano, M; Nessi-Tedaldi, F; Newman, H; Niessen, T; Nippe, A; Nisati, A; Nowak, H; Oh, Yu D; Opitz, H; Organtini, G; Ostonen, R; Palit, S; Palomares, C; Pandoulas, D; Paoletti, S; Paolucci, P; Park, H K; Park, I H; Pascale, G; Passaleva, G; Patricelli, S; Paul, T; Pauluzzi, M; Paus, C; Pauss, Felicitas; Peach, D; Pei, Y J; Pensotti, S; Perret-Gallix, D; Petersen, B; Petrak, S; Pevsner, A; Piccolo, D; Pieri, M; Piroué, P A; Pistolesi, E; Plyaskin, V; Pohl, M; Pozhidaev, V; Postema, H; Produit, N; Prokofev, D; Prokofiev, D O; Quartieri, J; Rahal-Callot, G; Raja, N; Rancoita, P G; Rattaggi, M; Raven, G; Razis, P A; Read, K; Ren, D; Rescigno, M; Reucroft, S; Van Rhee, T; Riemann, S; Riles, K; Rind, O; Robohm, A; Rodin, J; Roe, B P; Romero, L; Rosier-Lees, S; Rosselet, P; Van Rossum, W; Roth, S; Rubio, Juan Antonio; Ruschmeier, D; Rykaczewski, H; Salicio, J; Sánchez, E; Sanders, M P; Sarakinos, M E; Sarkar, S; Sauvage, G; Schäfer, C; Shchegelskii, V; Schmidt-Kärst, S; Schmitz, D; Schneegans, M; Scholz, N; Schopper, Herwig Franz; Schotanus, D J; Schwenke, J; Schwering, G; Sciacca, C; Sciarrino, D; Servoli, L; Shevchenko, S; Shivarov, N; Shoutko, V; Shukla, J; Shumilov, E; Shvorob, A V; Siedenburg, T; Son, D; Soulimov, V; Smith, B; Spillantini, P; Steuer, M; Stickland, D P; Stone, H; Stoyanov, B; Strässner, A; Sudhakar, K; Sultanov, G G; Sun, L Z; Susinno, G F; Suter, H; Swain, J D; Tang, X W; Tauscher, Ludwig; Taylor, L; Ting, Samuel C C; Ting, S M; Tonwar, S C; Tóth, J; Tully, C; Tuchscherer, H; Tung, K L; Uchida, Y; Ulbricht, J; Uwer, U; Valente, E; Vesztergombi, G; Vetlitskii, I; Viertel, Gert M; Vivargent, M; Vlachos, S; Völkert, R; Vogel, H; Vogt, H; Vorobev, I; Vorobyov, A A; Vorvolakos, A; Wadhwa, M; Wallraff, W; Wang, J C; Wang, X L; Wang, Z M; Weber, A; Wu, S X; Wynhoff, S; Xu, J; Xu, Z Z; Yang, B Z; Yang, C G; Yao, X Y; Ye, J B; Yeh, S C; You, J M; Zalite, A; Zalite, Yu; Zemp, P; Zeng, Y; Zhang, Z; Zhang, Z P; Zhou, B; Zhou, Y; Zhu, G Y; Zhu, R Y; Zichichi, Antonino; Ziegler, F

    1998-01-01

    Using the data collected with the L3 detector at LEP between 1990 and 1995, corresponding to an integrated luminosity of 149 pb$^{-1}$, the $\\tau$ longitudinal polarisation has been measured as a function of the production polar angle using the $\\tau$ decays \\thad\\ ($\\rm h = \\pi, \\rho, \\aone$) and \\tlep\\ ($\\rm \\ell = e, \\mu$). From this measurement the quantities æl~and \\at, which depend on the couplings of the electron and the $\\tau$ to the Z, are determined to be $\\ael = 0.1678 \\pm 0.0127 \\pm 0.0030 $ and $\\at = 0.1476 \\pm 0.0088 \\pm 0.0062$, consistent with the hypothesis of e--$\\tau$ universality. Under this assumption a value of $\\al = 0.1540 \\pm 0.0074 \\pm 0.0044 $ is obtained, yielding the value of the effective weak mixing angle $\\swsqb = 0.2306 \\pm 0.0011$.

  19. Polarisation resonance in X-ray diffraction

    International Nuclear Information System (INIS)

    Goodman, P.; Paterson, D.; Matheson, S.

    1994-01-01

    The study of crystal structures by means of dynamic X-ray diffraction has placed a challenge to theoreticians to revise the X-ray diffraction theory based on Maxwell's equation. In this paper the feasibility of using 'polarisation resonance' as a tool in the determination of absolute configuration for asymmetric structures is investigated. Two (left- and right-handed), σ + and σ- , circular polarization states for 3-beam conditions are considered. Moreover, extending interaction into the 3 rd. dimension (normal to the beam) opens the possibility of absolute configuration determination of asymmetric structures in 3 dimensions. The computational scheme used is shown in terms of scattering diagrams. 7 refs., 1 tab., 6 figs

  20. The spectral induced polarisation method and its application to hydrogeological problems

    International Nuclear Information System (INIS)

    Hoerdt, A.

    2007-01-01

    The spectral induced polarisation (SIP) method is an extension of the DC resistivity technique, where an alternating current is injected and the phase shift between voltage and current is measured in addition to the amplitude. In unconsolidated sediments, the phase shift includes complementary information on the structure of the pore space, and thus it should be possible to estimate hydraulic parameters from SIP measurements. Here, I describe some recent developments and give one example where hydraulic conductivity was estimated at the field scale

  1. Null point of discrimination in crustacean polarisation vision.

    Science.gov (United States)

    How, Martin J; Christy, John; Roberts, Nicholas W; Marshall, N Justin

    2014-07-15

    The polarisation of light is used by many species of cephalopods and crustaceans to discriminate objects or to communicate. Most visual systems with this ability, such as that of the fiddler crab, include receptors with photopigments that are oriented horizontally and vertically relative to the outside world. Photoreceptors in such an orthogonal array are maximally sensitive to polarised light with the same fixed e-vector orientation. Using opponent neural connections, this two-channel system may produce a single value of polarisation contrast and, consequently, it may suffer from null points of discrimination. Stomatopod crustaceans use a different system for polarisation vision, comprising at least four types of polarisation-sensitive photoreceptor arranged at 0, 45, 90 and 135 deg relative to each other, in conjunction with extensive rotational eye movements. This anatomical arrangement should not suffer from equivalent null points of discrimination. To test whether these two systems were vulnerable to null points, we presented the fiddler crab Uca heteropleura and the stomatopod Haptosquilla trispinosa with polarised looming stimuli on a modified LCD monitor. The fiddler crab was less sensitive to differences in the degree of polarised light when the e-vector was at -45 deg than when the e-vector was horizontal. In comparison, stomatopods showed no difference in sensitivity between the two stimulus types. The results suggest that fiddler crabs suffer from a null point of sensitivity, while stomatopods do not. © 2014. Published by The Company of Biologists Ltd.

  2. Light-front quantized field theory: (an introduction). Spontaneous symmetry breaking. Phase transition in φ4 theory

    International Nuclear Information System (INIS)

    Srivastava, P.P.

    1993-01-01

    The field theory quantized on the light-front is compared with the conventional equal-time quantized theory. The arguments based on the micro causality principle would imply that the light-front field theory may become nonlocal with respect to the longitudinal coordinate even though the corresponding equal-time formulation is local. This is found to be the case for the scalar theory. The conventional instant form theory is sometimes required to be constrained by invoking external physical considerations; the analogous conditions seem to be already built in the theory on the light-front. In spite of the different mechanisms of the spontaneous symmetry breaking in the two forms of dynamics they result in the same physical content. The phase transition in (φ 4 ) 2 theory is also discussed. The symmetric vacuum state for vanishingly small couplings is found to turn into an unstable symmetric one when the coupling is increased and may result in a phase transition of the second order in contrast to the first order transition concluded from the usual variational methods. (author)

  3. Wettability and surface free energy of polarised ceramic biomaterials

    International Nuclear Information System (INIS)

    Nakamura, Miho; Hori, Naoko; Namba, Saki; Yamashita, Kimihiro; Toyama, Takeshi; Nishimiya, Nobuyuki

    2015-01-01

    The surface modification of ceramic biomaterials used for medical devices is expected to improve osteoconductivity through control of the interfaces between the materials and living tissues. Polarisation treatment induced surface charges on hydroxyapatite, β-tricalcium phosphate, carbonate-substituted hydroxyapatite and yttria-stabilized zirconia regardless of the differences in the carrier ions participating in the polarisation. Characterization of the surfaces revealed that the wettability of the polarised ceramic biomaterials was improved through the increase in the surface free energies compared with conventional ceramic surfaces. (note)

  4. Anatomical and physiological evidence for polarisation vision in the nocturnal bee Megalopta genalis.

    Science.gov (United States)

    Greiner, Birgit; Cronin, Thomas W; Ribi, Willi A; Wcislo, William T; Warrant, Eric J

    2007-06-01

    The presence of a specialised dorsal rim area with an ability to detect the e-vector orientation of polarised light is shown for the first time in a nocturnal hymenopteran. The dorsal rim area of the halictid bee Megalopta genalis features a number of characteristic anatomical specialisations including an increased rhabdom diameter and a lack of primary screening pigments. Optically, these specialisations result in wide spatial receptive fields (Deltarho = 14 degrees ), a common adaptation found in the dorsal rim areas of insects used to filter out interfering effects (i.e. clouds) from the sky. In this specialised eye region all nine photoreceptors contribute their microvilli to the entire length of the ommatidia. These orthogonally directed microvilli are anatomically arranged in an almost linear, anterior-posterior orientation. Intracellular recordings within the dorsal rim area show very high polarisation sensitivity and a sensitivity peak within the ultraviolet part of the spectrum.

  5. Performance of a frozen spin polarised proton target

    International Nuclear Information System (INIS)

    Russell, F.M.

    1977-12-01

    The operational performance of a frozen spin polarised proton target specifically designed to give an unusually large angular access to the target has been examined. It is concluded that the mean absolute proton polarisation was held at about 64 +- 2% throughout the majority of HEP data recording. An excessive heat input to the target caused by inadequate cooling of the coaxial cable coupling to the nmr coil in the cavity seriously reduced the dwell-time of the target for HEP data collection. However, the short cooldown time of the target and minimal depolarisation associated with recycling of the target between polarising and HEP data collection positions resulted in only a small overall reduction in mean target polarisation and operational efficiency. (author)

  6. Polarisabilities and shielding factors for He, Ne and Ar

    International Nuclear Information System (INIS)

    McEachran, R.P.; Ryman, A.G.; Stauffer, A.D.

    1977-01-01

    Multipole polarisabilities and shielding factors for helium, neon and argon have been calculated accurately in the coupled Hartree-Fock approximation. A shell by shell analysis is given for the first four multipoles. (author)

  7. Field trial of GABA-fortified rice plants and oral administration of milled rice in spontaneously hypertensive rats.

    Science.gov (United States)

    Kowaka, Emi; Shimajiri, Yasuka; Kawakami, Kouhei; Tongu, Miki; Akama, Kazuhito

    2015-06-01

    Hypertension is one of the most critical risk factors accompanying cardiovascular diseases. γ-Aminobutyric acid (GABA) is a non-protein amino acid that functions as a major neurotransmitter in mammals and also as a blood-pressure lowering agent. We previously produced GABA-fortified rice lines of a popular Japonica rice cultivar 'Koshihikari' by genetic manipulation of GABA shunt-related genes. In the study reported here, we grew these same novel rice lines in a field trial and administered the milled rice orally to rats. The yield parameters of the transgenic rice plants were almost unchanged compared to those of untransformed cv. 'Koshihikari' plants, while the rice grains of the transgenic plants contained a high GABA content (3.5 g GABA/kg brown rice; 0.75-0.85 GABA g/kg milled rice) in a greenhouse trial. Oral administration of a diet containing 2.5% GABA-fortified rice, with a daily intake for 8 weeks, had an approximately 20 mmHg anti-hypertensive effect in spontaneous hypertensive rats but not in normotensive Wistar-Kyoto rats. These results suggest that GABA-fortified rice may be applicable as a staple food to control or prevent hypertension.

  8. Stark interaction of identical particles with the vacuum electromagnetic field as quantum Poisson process suppressing collective spontaneous emission

    International Nuclear Information System (INIS)

    Basharov, A. M.

    2011-01-01

    The effective Hamiltonian describing resonant interaction of an ensemble of identical quantum particles with a photon-free vacuum electromagnetic field has been obtained with allowance for terms of second order in the coupling constant (the Stark interaction) by means of the perturbation theory on the basis of the unitary transformation of the system quantum state. It has been shown that in the Markov approximation the effective Hamiltonian terms of first order in the coupling constant are represented by the quantum Wiener process, whereas terms of second order are expressed by the quantum Poisson process. During the course of the investigation, it was established that the Stark interaction played a significant role in the ensemble dynamics, thus influencing the collective spontaneous decay of the ensemble of an appreciably high number of identical particles. Fundamental effects have been discovered, i.e., the excitation conservation in a sufficiently dense ensemble of identical particles and superradiance suppression in the collective decaying process of an excited ensemble with a determined number of particles.

  9. Polarisation modulated crosscorrelation spectroscopy on a pulsed neutron source

    International Nuclear Information System (INIS)

    Cywinski, R.; Williams, W.G.

    1984-07-01

    A crosscorrelation technique is introduced by which a total scattering polarisation analysis spectrometer on a pulsed neutron source can be modified to give full neutron polarisation and energy analysis without changing the physical configuration of the instrument. Its implementation on the proposed POLARIS spectrometer at the Rutherford Appleton Laboratory Spallation Neutron Source is described, and the expected dynamic (Q, ω) range and resolution evaluated. (author)

  10. Measurement of the Tau Lepton Polarisation at LEP2

    CERN Document Server

    Abdallah, J.; Adam, W.; Adzic, P.; Albrecht, T.; Alemany-Fernandez, R.; Allmendinger, T.; Allport, P.P.; Amaldi, U.; Amapane, N.; Amato, Sandra F.; Anashkin, E.; Andreazza, A.; Andringa, S.; Anjos, N.; Antilogus, Pierre; Apel, W-D.; Arnoud, Y.; Ask, S.; Asman, B.; Augustin, Jean-Eudes; Augustinus, A.; Baillon, P.; Ballestrero, A.; Bambade, P.; Barbier, R.; Bardin, D.; Barker, G.J.; Baroncelli, Antonio; Battaglia, M.; Baubillier, M.; Becks, K-H.; Begalli, M.; Behrmann, A.; Ben-Haim, Eli; Benekos, N.; Benvenuti, A.; Berat, C.; Berggren, Mikael; Bertrand, D.; Besancon, M.; Besson, N.; Bloch, D.; Blom, M.; Bluj, Michal; Bonesini, Maurizio; Boonekamp, M.; Booth, P.S.L.; Borisov, G.; Botner, Olga; Bouquet, B.; Bowcock, T.J.V.; Boyko, I.; Bracko, Marko; Brenner, R.; Brodet, E.; Bruckman, P.; Brunet, J.M.; Buschbeck, B.; Buschmann, P.; Calvi, M.; Camporesi, Tiziano; Canale, V.; Carena, F.; Castro, Nuno Filipe; Cavallo, F.; Chapkin, M.; Charpentier, Ph.; Checchia, Paolo; Chierici, R.; Chliapnikov, P.; Chudoba, J.; Chung, Suh-Urk; Cieslik, K.; Collins, P.; Contri, Roberto; Cosme, G.; Cossutti, Fabio; Costa, M.J.; Crennell, D.; Cuevas, J.; D'Hondt, J.; da Silva, T.; Da Silva, W.; Dedovich, D.; Della Ricca, Giuseppe; De Angelis, Alessandro; De Boer, W.; De Clercq, C.; De Lotto, Barbara; De Maria, N.; De Min, A.; de Paula, L.; Di Ciaccio, L.; Di Simone, A.; Doroba, K.; Eigen, G.; Ekelof, Tord; Ellert, Mattias; Elsing, M.; Espirito Santo, Maria Catarina; Fanourakis, George K.; Feindt, Michael; Fernandez, J.; Ferrer, A.; Ferro, F.; Flagmeyer, U.; Foeth, H.; Fokitis, E.; Fulda-Quenzer, F.; Fuster, J.; Gandelman, Miriam; Garcia, C.; Gavillet, Philippe; Gazis, Evangelos; Gomez-Ceballos, G.; Goncalves, P.; Graziani, E.; Grosdidier, G.; Grzelak, K.; Guy, J.; Haag, C.; Hallgren, A.; Hamacher, Klaus; Hamilton, K.; Haug, S.; Hauler, F.; Hedberg, Vincent; Hennecke, M.; Herr, H.; Hoffman, J.; Holmgren, S-O.; Holt, P.J.; Houlden, M.A.; Jackson, John Neil; Jarlskog, Goran; Jarry, P.; Jeans, D.; Johansson, E.K.; Jonsson, P.; Joram, C.; Jungermann, L.; Kapusta, Frederic; Katsanevas, S.; Katsoufis, E.; Kernel, Gabrijel; Kerzel, U.; King, B.T.; Kjaer, N.J.; Kluit, Peter; Kokkinias, P.; Kourkoumelis, C.; Kouznetsov, O.; Krumstein, Z.; Kucharczyk, M.; Lamsa, J.; Leder, G.; Ledroit, F.; Leinonen, L.; Leitner, R.; Lemonne, Jacques; Lepeltier, V.; Lesiak, T.; Liebig, W.; Liko, D.; Lipniacka, A.; Lopes, J.H.; Lopez, J.M.; Loukas, D.; Lutz, Pierre; Lyons, Louis; MacNaughton, J.; Malek, A.; Maltezos, S.; Mandl, F.; Marco, J.; Marco, R.; Marechal, B.; Margoni, M.; Marin, J-C.; Mariotti, C.; Markou, Athanasios; Martinez-Rivero, C.; Masik, J.; Mastroyiannopoulos, N.; Matorras, Francisco; Matteuzzi, C.; Mazzucato, F.; Mazzucato, M.; Nulty, R.Mc; Meroni, C.; Migliore, E.; Mitaroff, Winfried A.; Mjoernmark, U.; Moa, T.; Moch, M.; Monge, R.; Montenegro, J.; Moraes, D.; Moreno, S.; Morettini, P.; Mueller, U.; Muenich, K.; Mulders, M.; Mundim Filho, Luiz Martins; Murray, W.; Muryn, B.; Myatt, G.; Myklebust, T.; Nassiakou, M.; Navarria, F.; Nawrocki, K.; Nicolaidou, R.; Oblakowska-Mucha, A.; Obraztsov, V.; Olshevski, A.; Onofre, A.; Orava, R.; Osterberg, K.; Ouraou, A.; Oyanguren, A.; Paganoni, M.; Paiano, S.; Palacios, J.P.; Palka, Henryk; Papadopoulou, Th.D.; Pape, L.; Parkes, C.; Parodi, F.; Parzefall, U.; Passeri, A.; Passon, O.; Peralta, L.; Perepelitsa, V.; Perrotta, Andrea; Petrolini, Alessandro; Piedra, Jonatan; Pieri, L.; Pierre, Francois; Pimenta, M.; Piotto, E.; Poireau, V.; Pol, M.E.; Polok, G.; Pozdniakov, V.; Pukhaeva, N.; Pullia, A.; Rames, J.; Read, A.; Rebecchi, P.; Rehn, J.; Reid, D.; Reinhardt, R.; Renton, Peter; Richard, F.; Ridky, Jan; Rivero, M.; Rodriguez, D.; Romero, A.; Ronchese, P.; Roudeau, P.; Rovelli, T.; Ruhlmann, Vanina; Ryabtchikov, D.; Sadovsky, A.; Salmi, L.; Salt, J.; Sander, C.; Savoy-Navarro, A.; Schwickerath, U.; Segar, A.; Sekulin, R.; Siebel, Martin; Sisakian, A.; Smadja, G.; Smirnova, O.; Sokolov, A.; Sopczak, A.; Sosnowski, R.; Spassov, T.; Stanitzki, M.; Stocchi, A.; Strauss, J.; Stugu, B.; Szczekowski, M.; Szeptycka, M.; Szumlak, T.; Tabarelli de Fatis, T.; Taffard, A.C.; Tegenfeldt, F.; Timmermans, Jan; Tkatchev, L.; Tobin, M.; Todorovova, S.; Tome, B.; Tonazzo, A.; Tortosa, P.; Travnicek, Petr; Treille, D.; Tristram, G.; Trochimczuk, M.; Troncon, Clara; Turluer, M-L.; Tyapkin, I.A.; Tyapkin, P.; Tzamarias, S.; Uvarov, V.; Valenti, Giovanni; Van Dam, P.; Van Eldik, J.; van Remortel, N.; Van Vulpen, I.; Vegni, G.; Veloso, F.; Venus, W.; Verdier, Patrice; Verzi, V.; Vilanova, D.; Vitale, Lorenzo; Vrba, V.; Wahlen, H.; Washbrook, A.J.; Weiser, C.; Wicke, D.; Wickens, J.; Wilkinson, G.; Winter, M.; Witek, M.; Yushchenko, O.; Zalewska, A.; Zalewski, P.; Zavrtanik, Danilo; Zhuravlov, V.; Zimine, N.I.; Zintchenko, Alexandre

    2008-01-01

    A first measurement of the average polarisation P_tau of tau leptons produced in e+e- annihilation at energies significantly above the Z resonance is presented. The polarisation is determined from the kinematic spectra of tau hadronic decays. The measured value P_tau = -0.164 +/- 0.125 is consistent with the Standard Model prediction for the mean LEP energy of 197 GeV.

  11. Deeply virtual Compton scattering off longitudinally polarised protons at HERMES

    International Nuclear Information System (INIS)

    Mahon, David Francis

    2010-03-01

    This thesis details the simultaneous extraction of three polarisation-dependent asymmetries in the distribution of real photons from the ep→epγ interaction and its indistinguishable deeply virtual Compton scattering and Bethe-Heitler processes at the HERMES fixed-target experiment at Desy. The data analysed were taken using a longitudinally polarised 27.57 GeV positron beam incident on a longitudinally polarised hydrogen gas target. The extracted asymmetries include two single-spin asymmetries A UL and A LU which depend on the polarisation of the target and beam respectively, averaged over all other polarisation states. The double-spin asymmetry A LL dependent on the product of the beam and target polarisations is extracted for the first time. The asymmetry amplitudes extracted relate to combinations of Generalised Parton Distributions (GPDs), predominantly H and H. The extracted amplitudes are presented across the HERMES kinematic range alongside theoretical predictions from a GPD model based on double distributions. Large sin φ and cos(0φ) amplitudes are observed for A UL and A LL respectively, with an unexpectedly large sin(2φ) amplitude for A UL . The results for the A UL and A LL asymmetries are broadly compatible with theory predictions, and the extracted A LU amplitudes are compatible with HERMES results extracted from a significantly larger data set. It is foreseen that these results will form input to future global data-based GPD models which aim to provide a better understanding of GPDs. (orig.)

  12. The sunstone and polarised skylight: ancient Viking navigational tools?

    Science.gov (United States)

    Ropars, Guy; Lakshminarayanan, Vasudevan; Le Floch, Albert

    2014-10-01

    Although the polarisation of the light was discovered at the beginning of the nineteenth century, the Vikings could have used the polarised light around the tenth century in their navigation to America, using a 'sunstone' evoked in the Icelandic Sagas. Indeed, the birefringence of the Iceland spar (calcite), a common crystal in Scandinavia, permits a simple observation of the axis of polarisation of the skylight at the zenith. From this, it is possible to guess the azimuth of a hidden Sun below the horizon, for instance. The high sensitivity of the differential method provided by the ordinary and extraordinary beams of calcite at its so-called isotropy point is about two orders higher than that of the best dichroic polariser and permits to reach an accuracy of ±1° for the Sun azimuth (at sunrise and sunset). Unfortunately, due to the relative fragility of calcite, only the so-called Alderney crystal was discovered on board a 16th ancient ship. Curiously, beyond its use as a sunstone by the Vikings, during these last millennia calcite has led to the discovery of the polarisation of the light itself by Malus and is currently being used to detect the atmospheres of exoplanets. Moreover, the differential method for the light polarisation detection is widely used in the animal world.

  13. Polarised infrared cathodoluminescence from platelet defects in natural diamonds

    International Nuclear Information System (INIS)

    Kiflawi, I.; Lang, A.R.

    1977-01-01

    It is reported that the large platelet defects occasionally found in natural diamonds emit polarised cathodoluminescence in the near infrared. There is much uncertainty regarding the composition and structure of the platelets. New findings on the optical properties of the platelets are discussed. The discovery that cathodoluminescence from giant platelets can be seen in the near infrared using an image converter was followed up by photographic recording with Kodak high speed infrared films, and it was found that the infrared emission from the platelets is polarised in the platelet plane with a considerably higher polarisation ratio than in the case of their visible emissions. In order to assess the degree of polarisation of the infrared emission a Polaroid Type HR linear polariser was used, which is very effective at the longest wavelengths recorded by the Kodak high speed infrared film. The high degree of polarisation of the platelet infrared emission constitutes a well defined optical characteristic that any model for platelet structure, and for optical processes associated with platelets, must satisfactorily accommodate. (U.K.)

  14. Polarised nuclei for neutron science: recent applications and perspectives

    International Nuclear Information System (INIS)

    Glaettli, Hans

    2004-01-01

    Neutron scattering on nuclei is spin dependent, particularly strongly for 1 H. The means to achieve large nuclear polarisations and its use for structure analysis or as spin-handling device are reviewed. High resolution (diffraction) as well as low resolution (SANS) measurements can benefit from polarised nuclei by changing selectively the form factors of Bragg reflections or the contrasts (the scattering length density profiles) in SANS. The internal structure of ribosomes and the conformation of polymers in solution have been investigated by this method. A numerical simulation is presented to show the influence of steady-state polarisation of protons on the scattering from a protein-ARN model complex. In addition, a more recent technique, time-resolved SANS is described. It makes use of spatial polarisation gradients created around paramagnetic centres at the onset of nuclear polarisation. Such polarisation domains can enhance considerably the scattering amplitude of free radicals and thus contribute to determine their positions inside a complex protein. Examples of possible future experiments are proposed which combine simultaneously the selectivity of solid-state NMR techniques and neutron scattering

  15. The gluon contribution to polarised nucleon structure functions

    International Nuclear Information System (INIS)

    Ross, G.G.; Roberts, R.G.

    1990-08-01

    As with all parton distributions in quantum chromodynamics (QCD) the separation of polarised nucleon structure functions into gluon and quark contributions must be specified. We consider a definition of the gluon contribution to polarised nucleon structure functions based on exclusive processes which is explicitly gauge invariant, has no regularisation ambiguities, is insensitive to infrared singularities and can be related to other polarised scattering processes. We discuss the relationship of this gluon definition to others that have recently been used and to the estimates that have been made of the gluon contribution using current algebra and other methods. A quantitative analysis of the structure function g 1 (x,Q 2 ) for polarised deep inelastic scattering is carried out, with the aim of examining the importance of the gluon contribution. Using the positivity of parton distributions the magnitude of Δg(x,Q 2 ) is constrained by a realistic estimate of the unpolarised glue. With the appropriate choice of the hard scattering cross-section, Δσ γg , we find that even with a maximally polarised glue (for x > 0.1), some polarised strange quark contribution is still needed by the data of the EMC. (author)

  16. Measurement of the SMC muon beam polarisation using the asymmetry in the elastic scattering off polarised electrons

    CERN Document Server

    Adams, D; Adeva, B; Akdogan, T; Arik, E; Arvidson, A; Badelek, B; Bardin, G; Baum, G; Berglund, P; Betev, L; Birsa, R; Björkholm, P; Bonner, B E; De Botton, N R; Boutemeur, M; Bradamante, Franco; Bravar, A; Bressan, A; Bültmann, S; Burtin, E; Cavata, C; Clocchiatti, M; Crabb, D; Cranshaw, J; Çuhadar-Dönszelmann, T; Dalla Torre, S; Van Dantzig, R; Derro, B R; Deshpande, A A; Dhawan, S K; Dulya, C M; Dyring, A; Eichblatt, S; Faivre, Jean-Claude; Fasching, D; Feinstein, F; Fernández, C; Forthmann, S; Frois, Bernard; Gallas, A; Garzón, J A; Gatignon, L; Gaussiran, T; Gilly, H; Giorgi, M A; von Goeler, E; Görtz, S; Golutvin, I A; Gracia, G; De Groot, N; Grosse-Perdekamp, M; Haft, K; Von Harrach, D; Hasegawa, T; Hautle, P; Hayashi, N; Heusch, C A; Horikawa, N; Hughes, V W; Igo, G; Ishimoto, S; Iwata, T; Kabuss, E M; Kageya, T; Karev, A G; Kessler, H J; Ketel, T; Kiryluk, J; Kiryushin, Yu T; Kishi, A; Kiselev, Yu F; Klostermann, L; Krämer, Dietrich; Krivokhizhin, V G; Kröger, W; Kukhtin, V V; Kurek, K; Kyynäräinen, J; Lamanna, M; Landgraf, U; Le Goff, J M; Lehár, F; de Lesquen, A; Lichtenstadt, J; Lindqvist, T; Litmaath, M; Loewe, M; Magnon, A; Mallot, G K; Marie, F; Martin, A; Martino, J; Matsuda, T; Mayes, B W; McCarthy, J S; Medved, K S; Meyer, W T; Van Middelkoop, G; Miller, D; Miyachi, Y; Mori, K; Moromisato, J H; Nagaitsev, A P; Nassalski, J P; Naumann, Lutz; Niinikoski, T O; Oberski, J; Ogawa, A; Ozben, C; Pereira, H; Perrot-Kunne, F; Peshekhonov, V D; Piegaia, R; Pinsky, L; Platchkov, S K; Pló, M; Pose, D; Postma, H; Pretz, J; Pussieux, T; Rädel, G; Rijllart, A; Reicherz, G; Roberts, J B; Rock, S E; Rodríguez, M; Rondio, Ewa; Ropelewski, Leszek; Sabo, I; Saborido, J; Sandacz, A; Savin, I A; Schiavon, R P; Schiller, A; Schüler, K P; Seitz, R; Semertzidis, Y K; Sergeev, S; Shanahan, P; Sichtermann, E P; Simeoni, F; Smirnov, G I; Staude, A; Steinmetz, A; Stiegler, U; Stuhrmann, H B; Szleper, M; Tessarotto, F; Thers, D; Tlaczala, W; Tripet, A; Ünel, G; Velasco, M; Vogt, J; Voss, Rüdiger; Whitten, C; Windmolders, R; Willumeit, R; Wislicki, W; Witzmann, A; Ylöstalo, J; Zanetti, A M; Zaremba, K; Zamiatin, N I; Zhao, J

    2000-01-01

    A muon beam polarimeter was built for the SMC experiment at the CERN SPS, for beam energies of 100 and 190 GeV. The beam polarisation is determined from the asymmetry in the elastic scattering off the polarised electrons of a ferromagnetic target whose magnetisation is periodically reversed. At muon energies of 100 and 190~GeV the measured polarisation is $P_{\\mu}=-0.80 \\pm 0.03 (stat.)\\pm 0.02 (syst.)$ and $P_{\\mu}=-0.797 \\pm 0.011 (stat.)\\pm 0.012 (syst.)$, respectively. These results agree with measurements of the beam polarisation using a shape analysis of the decay positron energy spectrum.

  17. Counterintuitive electron localisation from density-functional theory with polarisable solvent models

    Energy Technology Data Exchange (ETDEWEB)

    Dale, Stephen G., E-mail: sdale@ucmerced.edu [Chemistry and Chemical Biology, School of Natural Sciences, University of California, Merced, 5200 North Lake Road, Merced, California 95343 (United States); Johnson, Erin R., E-mail: erin.johnson@dal.ca [Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, Nova Scotia B3H 4R2 (Canada)

    2015-11-14

    Exploration of the solvated electron phenomena using density-functional theory (DFT) generally results in prediction of a localised electron within an induced solvent cavity. However, it is well known that DFT favours highly delocalised charges, rendering the localisation of a solvated electron unexpected. We explore the origins of this counterintuitive behaviour using a model Kevan-structure system. When a polarisable-continuum solvent model is included, it forces electron localisation by introducing a strong energetic bias that favours integer charges. This results in the formation of a large energetic barrier for charge-hopping and can cause the self-consistent field to become trapped in local minima thus converging to stable solutions that are higher in energy than the ground electronic state. Finally, since the bias towards integer charges is caused by the polarisable continuum, these findings will also apply to other classical polarisation corrections, as in combined quantum mechanics and molecular mechanics (QM/MM) methods. The implications for systems beyond the solvated electron, including cationic DNA bases, are discussed.

  18. The Ringo2 Optical Polarisation Catalogue of 13 High-Energy Blazars

    Science.gov (United States)

    Barres de Almeida, Ulisses; Jermak, Helen; Mundell, Carole; Lindfors, Elina; Nilsson, Kari; Steele, Iain

    2015-08-01

    We present the findings of the Ringo2 3-year survey of 13 blazars (3 FSRQs and 10 BL Lacs) with regular coverage and reasonably fast cadence of one to three observations a week. Ringo2 was installed on the Liverpool Robotic Telescope (LT) on the Canary Island of La Palma between 2009 and 2012 and monitored thirteen high-energy-emitting blazars in the northern sky. The objects selected as well as the observational strategy were tuned to maximise the synergies with high-energy X- to gamma-ray observations. Therefore this sample stands out as a well-sampled, long-term view of high-energy AGN jets in polarised optical light. Over half of the sources exhibited an increase in optical flux during this period and almost a quarter were observed in outburst. We compare the optical data to gamma (Fermi/LAT) and X-ray data during these periods of outburst. In this talk we present the data obtained for all sources over the lifetime of Ringo2 with additional optical data from the KVA telescope and the SkyCamZ wide-field camera (on the LT), we explore the relationship between the change in polarisation angle as a function of time (dEVPA/dMJD), flux and polarisation degree along with cross correlation comparisons of optical and high-energy flux.

  19. Realization of the purely spatial Einstein-Podolsky-Rosen paradox in full-field images of spontaneous parametric down-conversion

    Science.gov (United States)

    Moreau, Paul-Antoine; Mougin-Sisini, Joé; Devaux, Fabrice; Lantz, Eric

    2012-07-01

    We demonstrate Einstein-Podolsky-Rosen (EPR) entanglement by detecting purely spatial quantum correlations in the near and far fields of spontaneous parametric down-conversion generated in a type-2 beta barium borate crystal. Full-field imaging is performed in the photon-counting regime with an electron-multiplying CCD camera. The data are used without any postselection, and we obtain a violation of Heisenberg inequalities with inferred quantities taking into account all the biphoton pairs in both the near and far fields by integration on the entire two-dimensional transverse planes. This ensures a rigorous demonstration of the EPR paradox in its original position-momentum form.

  20. Effect of thermomagnetic treatment on the magnetic state of a ferrofluid: a polarised neutron study

    Energy Technology Data Exchange (ETDEWEB)

    Zabenkin, V.N.; Axelrod, L.A.; Gordeev, G.P.; Kraan, W.H.; Lazebnik, I.M.; Vorobiev, A.A

    2004-07-15

    In magnetic colloids of sufficiently high particle concentration, frustration of dipolar interactions could arise as found in spin-glass systems. To understand this situation, a ferrofluid consisting of magnetite particles was frozen in either a horizontal or a vertical field and then 3D neutron-polarisation analysis was performed around the hysteresis loop in both field configurations. The same was done in the fluid state. A comparison of the data leads to the conclusion that frustration plays a key role in the self-organisation of nanoparticles in a frozen magnetic colloid.

  1. Beam-induced depolarisation at the HERMES transversely polarised hydrogen target

    International Nuclear Information System (INIS)

    Tait, P.

    2006-01-01

    This thesis describes the polarised hydrogen target of the HERMES experiment at DESY in Hamburg. The HERMES target is based on hyperfine-splitting of hydrogen in an external magnetic field and provides nuclear-polarised hydrogen for the HERMES experiment. Particular emphasis is placed on the phenomenon of beam-induced depolarisation. The HERA electron beam consists of short bunches which produce a high-frequency magnetic field. A Fourier analysis of these bunches leads to a series of harmonics, based on the fundamental frequency of roughly 10.4 MHz, which can cause a transition between hyperfine states of the target atoms. Only through careful setting of the external magnetic field is it possible to avoid these transitions and the resulting depolarisation of the target gas. Measurements of these resonances were made during the first HERMES run 1995-2000. The target region was modified in 2001 to allow HERMES to use hydrogen polarised perpendicularly to the direction of the electron beam. This modification gave HERMES access to the so-called 'Transversity' distribution for the first time, but also allows additional resonances in the target, which were previously forbidden by selection rules. The measurement and minimisation of these 'Sigma resonances' are presented. A distinctive feature of the HERMES experiment is its novel storage cell which allows target atoms to make multiple passes of the HERA beam. An exact description of beam-induced depolarisation must therefore consider the geometry of the storage cell and the distribution of the magnetic field throughout the cell. Calculations of the depolarisation can be made by solving the time-dependent Schroedinger equation using first-order perturbation theory. A simple analytical model and a molecular-flow Monte-Carlo are used to predict the exact shape of the resonances. The first measurements of the resonances with a transverse magnetic holding field are presented and compared with the simulations. (orig.)

  2. Output Beam Polarisation of X-ray Lasers with Transient Inversion

    Science.gov (United States)

    Janulewicz, K. A.; Kim, C. M.; Matouš, B.; Stiel, H.; Nishikino, M.; Hasegawa, N.; Kawachi, T.

    It is commonly accepted that X-ray lasers, as the devices based on amplified spontaneous emission (ASE), did not show any specific polarization in the output beam. The theoretical analysis within the uniform (single-mode) approximation suggested that the output radiation should show some defined polarization feature, but randomly changing from shot-to-shot. This hypothesis has been verified by experiment using traditional double-pulse scheme of transient inversion. Membrane beam-splitter was used as a polarization selector. It was found that the output radiation has a significant component of p-polarisation in each shot. To explain the effect and place it in the line with available, but scarce data, propagation and kinetic effects in the non-uniform plasma have been analysed.

  3. Polarisation independent bi-directional four wave mixing for mid span spectral inversion

    DEFF Research Database (Denmark)

    Clausen, Anders; Buxens, Alvaro A.; Poulsen, Henrik Nørskov

    1999-01-01

    Polarisation independent Four Wave Mixing in a Semiconductor Optical Amplifier used for Mid Span Spectral Inversion (MSSI) is implemented and introduce only 0.9 dB penalty compared to polarisation dependent MSSI. The polarisation dependence in receiver sensitivity is 1 dB.......Polarisation independent Four Wave Mixing in a Semiconductor Optical Amplifier used for Mid Span Spectral Inversion (MSSI) is implemented and introduce only 0.9 dB penalty compared to polarisation dependent MSSI. The polarisation dependence in receiver sensitivity is 1 dB....

  4. Effect of etorphine on the spontaneous and field stimulation-mediated release of norepinephrine and total tritium from perfused guinea pig hearts

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    Isolated guinea pig hearts were prelabeled with 3 H-norepinephrine ( 3 H-NE) and perfused with modified Krebs-bicarbonate solution at 37 0 C. Spontaneous release of total 3 H and field stimulation-mediated (supramax. V., 1 Hz, 2 msec duration for a total of 60 pulses) overflow of NE and 3 H-NE were measured in the absence or presence of etorphine. Etorphine (0.1 - 100 μM) was added to the perfusion fluid 15 min. before the stimulation. To study the effect of etorphine on spontaneous release of total 3 H, etorphine was added cumulatively without stimulation. Etorphine (1.0 - 100 μM) caused a significant decrease in the stimulation-mediated overflow of NE and the inhibition was dose-related. The overflow of NE was 5.1 +/- 0.3 ng in the absence and 4.0 +/- 0.2 ng in the presence of etorphine (1.0 μM). Low concentrations of etorphine (0.1 - 1.0 μM) had no effect on the spontaneous release of total 3 H while 10 μM and 100 μM caused a 3 and 6-fold increase respectively. The results show that etorphine inhibited neuronal release of NE at a dose which had no effect on spontaneous release. It is suggested that opiate receptors might be involved in the prejunctional modulation of the release of NE in the guinea pig heart

  5. Polarised IR-microscope spectra of guanidinium hydrogensulphate single crystal.

    Science.gov (United States)

    Drozd, M; Baran, J

    2006-07-01

    Polarised IR-microscope spectra of C(NH(2))(3)*HSO(4) small single crystal samples were measured at room temperature. The spectra are discussed on the basis of oriented gas model approximation and group theory. The stretching nuOH vibration of the hydrogen bond with the Ocdots, three dots, centeredO distance of 2.603A gives characteristic broad AB-type absorption in the IR spectra. The changes of intensity of the AB bands in function of polariser angle are described. Detailed assignments for bands derived from stretching and bending modes of sulphate anions and guanidinium cations were performed. The observed intensities of these bands in polarised infrared spectra were correlated with theoretical calculation of directional cosines of selected transition dipole moments for investigated crystal. The vibrational studies seem to be helpful in understanding of physical and chemical properties of described compound and also in design of new complexes with exactly defined behaviors.

  6. Deeply virtual Compton scattering off longitudinally polarised protons at HERMES

    Energy Technology Data Exchange (ETDEWEB)

    Mahon, David Francis

    2010-06-15

    This thesis details the simultaneous extraction of three polarisation-dependent asymmetries in the distribution of real photons from the ep{yields}ep{gamma} interaction and its indistinguishable deeply virtual Compton scattering and Bethe-Heitler processes at the HERMES fixed-target experiment at Desy. The data analysed were taken using a longitudinally polarised 27.57 GeV positron beam incident on a longitudinally polarised hydrogen gas target. The extracted asymmetries include two single-spin asymmetries A{sub UL} and A{sub LU} which depend on the polarisation of the target and beam respectively, averaged over all other polarisation states. The double-spin asymmetry A{sub LL} dependent on the product of the beam and target polarisations is extracted for the first time. The asymmetry amplitudes extracted relate to combinations of Generalised Parton Distributions (GPDs), predominantly H and H. The extracted amplitudes are presented across the HERMES kinematic range alongside theoretical predictions from a GPD model based on double distributions. Large sin {phi} and cos(0{phi}) amplitudes are observed for A{sub UL} and A{sub LL} respectively, with an unexpectedly large sin(2{phi}) amplitude for A{sub UL}. The results for the A{sub UL} and A{sub LL} asymmetries are broadly compatible with theory predictions, and the extracted A{sub LU} amplitudes are compatible with HERMES results extracted from a significantly larger data set. It is foreseen that these results will form input to future global data-based GPD models which aim to provide a better understanding of GPDs. (orig.)

  7. Physics in the intrinsic coordinate frames with the universal mean field potential: spontaneous parity breaking and exotic shapes in high-spin states

    International Nuclear Information System (INIS)

    Dudek, J.

    1989-01-01

    The concept of a ''universal'' average field as a basis of intrinsic-frame nuclear physics is stressed. The symmetries of such an average field are discussed. As an important application, an overwiew is given of the recent progress in understanding the octupole-type (intrinsic-parity breaking) degrees of freedom in nuclei. Their importance and the new consequences resulting from the related symmetries and spontaneous symmetry breaking phenomena are emphasized: the presence of static and/or dynamic isovector deformations and their implications, the possible low-energy E1 cooling in moderately hot nuclei at high spins, possible new forms of rotational dumping effects in rotating nuclei etc

  8. Linearly polarised photons at the BGO-OD experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bella, Andreas [Physikalisches Institut, Universitaet Bonn (Germany)

    2016-07-01

    The BGO-OD experiment, located at the ELSA accelerator of the University of Bonn studies photoproduction reactions off the nucleon. A real, energy-tagged photon beam is produced via bremsstrahlung by exposing a thin radiator to the electron beam provided by ELSA. Linear polarisation is obtained by coherent bremsstrahlung. To do this we use a 570 μm thick diamond radiator. The degree of polarisation is obtained from the bremsstrahlung spectrum. A consistency check is performed by extracting the already well measured beam asymmetry Σ in π{sup 0} photoproduction off the proton.

  9. Polarisation Spectral Synthesis For Type Ia Supernova Explosion Models

    Science.gov (United States)

    Bulla, Mattia

    2017-02-01

    Despite their relevance across a broad range of astrophysical research topics, Type Ia supernova explosions are still poorly understood and answers to the questions of when, why and how these events are triggered remain unclear. In this respect, polarisation offers a unique opportunity to discriminate between the variety of possible scenarios. The observational evidence that Type Ia supernovae are associated with rather low polarisation signals (smaller than a few per cent) places strong constraints for models and calls for modest asphericities in the progenitor system and/or explosion mechanism.The goal of this thesis is to assess the validity of contemporary Type Ia supernova explosion models by testing whether their predicted polarisation signatures can account for the small signals usually observed. To this end, we have implemented and tested an innovative Monte Carlo scheme in the radiative transfer code artis. Compared to previous Monte Carlo approaches, this technique produces synthetic observables (light curves, flux and polarisation spectra) with a substantial reduction in the Monte Carlo noise and therefore in the required computing time. This improvement is particularly crucial for our study as we aim to extract very weak polarisation signals, comparable to those detected in Type Ia supernovae. We have also demonstrated the applicability of this method to other classes of supernovae via a preliminary study of the first spectropolarimetry observations of superluminous supernovae.Using this scheme, we have calculated synthetic spectropolarimetry for three multi-dimensional explosion models recently proposed as promising candidates to explain Type Ia supernovae. Our findings highlight the power of spectropolarimetry in testing and discriminating between different scenarios. While all the three models predict light curves and flux spectra that are similar to each others and reproduce those observed in Type Ia supernovae comparably well, polarisation does

  10. The Gender Dimension of Technical Change and Job Polarisation

    OpenAIRE

    Joanne Lindley

    2010-01-01

    Many studies have shown that technical change has led to job polarisation. A relatively unexplored aspect of this is whether there has been a gender bias. This paper is the first to show gender bias in technology driven skill polarisation. Between 1997 and 2006 the demand for women shows hollowing out across high, medium and low education groups, as a consequence of technical change. This was not the case for men. Decomposing the fall in the gender pay gap shows further evidence for gender bi...

  11. Low-frequency-field-induced spontaneous-emission interference in a two-level atom placed in an anisotropic photonic crystal

    International Nuclear Information System (INIS)

    Li Gaoxiang; Evers, Joerg; Keitel, Christoph H

    2005-01-01

    We investigate the spontaneous-emission properties of a two-level atom embedded in a three-dimensional anisotropic photonic crystal. In addition to the modified density of states, the atom is driven by a coherent intense low-frequency field (LFF), which creates additional multiphoton decay channels with the exchange of two low-frequency photons and one spontaneous photon during an atomic transition. Due to the low frequency of the applied field, the various transition pathways may interfere with each other and thus give rise to a modified system dynamics. We find that even if all the atomic (bare and induced) transition frequencies are in the conducting band of the photonic crystal, there still may exist a photon-atom bound state in coexistence with propagating modes. The system also allows us to generate narrow lines in the spontaneous-emission spectrum. This spectrum is a function of the distance of the observer from the atom due to the band gap in the photonic crystal. The system properties depend on three characteristic frequencies, which are influenced by quantum interference effects. Thus these results can be attributed to a combination of interference and band-gap effects

  12. The effect of cathodic polarisation on monosaccharides of Amphora coffeaeformis, a marine fouling diatom

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Evans, L.V.; Edyvean, R.G.J.

    The composition of monosaccharides and their variation in concentration in Amphora coffeaeformis cells on non-polarised and cathodically polarised 304 stainless steel were examined when cells were grown under continous illumination at 18~'C for 8 d...

  13. OPTICAL FIBRES AND FIBREOPTIC SENSORS: Polarisation reflectometry of anisotropic optical fibres

    Science.gov (United States)

    Konstantinov, Yurii A.; Kryukov, Igor'I.; Pervadchuk, Vladimir P.; Toroshin, Andrei Yu

    2009-11-01

    Anisotropic, polarisation-maintaining fibres have been studied using a reflectometer and integrated optic polariser. Linearly polarised pulses were launched into the fibre under test at different angles between their plane of polarisation and the main optical axis of the fibre. A special procedure for the correlation analysis of these reflectograms is developed to enhance the reliability of the information about the longitudinal optical uniformity ofanisotropic fibres.

  14. Training-induced inversion of spontaneous exchange bias field on La{sub 1.5}Ca{sub 0.5}CoMnO{sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Bufaiçal, L., E-mail: lbufaical@ufg.br [Instituto de Física, Universidade Federal de Goiás, 74001-970 Goiânia, GO (Brazil); Finkler, R.; Coutrim, L.T. [Instituto de Física, Universidade Federal de Goiás, 74001-970 Goiânia, GO (Brazil); Pagliuso, P.G. [Instituto de Física “Gleb Wataghin”, UNICAMP, 13083-859 Campinas, SP (Brazil); Grossi, C.; Stavale, F.; Baggio-Saitovitch, E.; Bittar, E.M. [Centro Brasileiro de Pesquisas Físicas, Rua Dr. Xavier Sigaud 150, 22290-180 Rio de Janeiro, RJ (Brazil)

    2017-07-01

    Highlights: • La{sub 1.5}Ca{sub 0.5}CoMnO{sub 6} exhibits spontaneous exchange bias effect at low temperature. • For successive hysteresis cycles it inverts the shift sign from negative to positive. • For a field cooled hysteresis cycle, the exchange bias effect greatly enhances. • Our results are compared to those of the analogue compound La{sub 1.5}Sr{sub 0.5}CoMnO{sub 6}. - Abstract: In this work we report the synthesis and structural, electronic and magnetic properties of La{sub 1.5}Ca{sub 0.5}CoMnO{sub 6} double-perovskite. This is a re-entrant spin cluster material which exhibits a non-negligible negative exchange bias effect when it is cooled in zero magnetic field from an unmagnetized state down to low temperature. X-ray powder diffraction, X-ray photoelectron spectroscopy and magnetometry results indicate mixed valence state at Co site, leading to competing magnetic phases and uncompensated spins at the magnetic interfaces. We compare the results for this Ca-doped material with those reported for the resemblant compound La{sub 1.5}Sr{sub 0.5}CoMnO{sub 6}, and discuss the much smaller spontaneous exchange bias effect observed for the former in terms of its structural and magnetic particularities. For La{sub 1.5}Ca{sub 0.5}CoMnO{sub 6}, when successive magnetization loops are carried, the spontaneous exchange bias field inverts its sign from negative to positive from the first to the second measurement. We discuss this behavior based on the disorder at the magnetic interfaces, related to the presence of a glassy phase. This compound also exhibits a large conventional exchange bias, for which there is no sign inversion of the exchange bias field for consecutive cycles.

  15. Optimising polarised neutron scattering measurements--XYZ and polarimetry analysis

    International Nuclear Information System (INIS)

    Cussen, L.D.; Goossens, D.J.

    2002-01-01

    The analytic optimisation of neutron scattering measurements made using XYZ polarisation analysis and neutron polarimetry techniques is discussed. Expressions for the 'quality factor' and the optimum division of counting time for the XYZ technique are presented. For neutron polarimetry the optimisation is identified as analogous to that for measuring the flipping ratio and reference is made to the results already in the literature

  16. Optimising polarised neutron scattering measurements--XYZ and polarimetry analysis

    CERN Document Server

    Cussen, L D

    2002-01-01

    The analytic optimisation of neutron scattering measurements made using XYZ polarisation analysis and neutron polarimetry techniques is discussed. Expressions for the 'quality factor' and the optimum division of counting time for the XYZ technique are presented. For neutron polarimetry the optimisation is identified as analogous to that for measuring the flipping ratio and reference is made to the results already in the literature.

  17. Flux and polarisation spectra of water clouds on exoplanets

    NARCIS (Netherlands)

    Karalidi, T.; Stam, D.M.; Hovenier, J.W.

    2011-01-01

    Context. A crucial factor for a planet’s habitability is its climate. Clouds play an important role in planetary climates. Detecting and characterising clouds on an exoplanet is therefore crucial when addressing this planet’s habitability. Aims. We present calculated flux and polarisation spectra of

  18. Polarised Drell-Yan measurements at $\\mathrm{COMPASS}$

    CERN Document Server

    Chiosso, Michela

    2015-01-01

    Much of the information that exists today about Transverse Momentum Dependent Parton Distribution Functions (TMDs) comes from SIDIS measurements with unpolarised and polarised beams and targets where they appear convoluted with fragmentation functions (FFs). Drell-Yan (DY) measurements are complementary to those by SIDIS experiments, as they allow to measure convolutions of only Parton Distribution Functions (PDFs) without involving FFs. Moreover, given the T-odd character of both Sivers and Boer-Mulders functions, the sign of these TMDs is expected to be reversed when observed from SIDIS or from DY. Measurements of SIDIS were performed by Compass in the period 2002 to 2007 and in 2010, using a naturally polarised μ+ beam and a solid state target polarised either longitudinally or transversely with respect to the beam direction. Now the COMPASS Experiment has the unique opportunity to access TMDs from single-polarised Drell-Yan processes as well, in the same kinematical domain of the SIDIS data and with the ...

  19. Efforts towards a dynamically polarised HD-target

    International Nuclear Information System (INIS)

    Radtke, E.; Goertz, St.; Harmsen, J.; Heckmann, J.; Meier, A.; Meyer, W.; Reicherz, G.

    2004-01-01

    The molecular hydrogen isotopes contain no unpolarisable background. From this point of view they appear to be the material of choice for a polarised bulk target in scattering experiments. The fast nuclear relaxation of H 2 and D 2 is one reason that these substances are not highly polarisable. This fact brings hydrogendeuteride (HD) into focus. In Bochum a device to freeze out gases into the consisting 4 He-cryostat has been built up. The principle of the Dynamic Nuclear Polarisation requires a sufficient amount of paramagnetic electrons. These have been produced by cracking HD molecules at 1 K using a 90 Sr β-source with an activity of 3.7 GBq. Six days of effective irradiation resulted in a density of paramagnetic centres in the order of 10 18 spins/cm 3 . This could be estimated from bolometric electron paramagnetic resonance (EPR) measurements. Dynamic polarisation could not be achieved. This is accounted to isotopic impurities in the used HD, which accelerate the nuclear relaxation. The constant of ortho-para conversion in H 2 could be confirmed to be 1.9%/h

  20. The Polarised Valence Quark Distribution from semi-inclusive DIS

    CERN Document Server

    Alekseev, M.; Alexandrov, Yu.; Alexeev, G.D.; Amoroso, A.; Arbuzov, A.; Badelek, B.; Balestra, F.; Ball, J.; Barth, J.; Baum, G.; Bedfer, Y.; Bernet, C.; Bertini, R.; Bettinelli, M.; Birsa, R.; Bisplinghoff, J.; Bordalo, P.; Bradamante, F.; Bravar, A.; Bressan, A.; Brona, G.; Burtin, E.; Bussa, M.P.; Chapiro, A.; Chiosso, M.; Cicuttin, A.; Colantoni, M.; Costa, S.; Crespo, M.L.; Dalla Torre, S.; Dafni, T.; Das, S.; Dasgupta, S.S.; De Masi, R.; Dedek, N.; Denisov, O.Yu.; Dhara, L.; Diaz, V.; Dinkelbach, A.M.; Donskov, S.V.; Dorofeev, V.A.; Doshita, N.; Duic, V.; Dunnweber, W.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Falaleev, V.; Ferrero, A.; Ferrero, L.; Finger, M.; Finger, M., Jr.; Fischer, H.; Franco, C.; Franz, J.; Friedrich, J.M.; Frolov, V.; Garfagnini, R.; Gautheron, F.; Gavrichtchouk, O.P.; Gazda, R.; Gerassimov, S.; Geyer, R.; Giorgi, M.; Gobbo, B.; Goertz, S.; Gorin, A.M.; Grabmuller, S.; Grajek, O.A.; Grasso, A.; Grube, B.; Gushterski, R.; Guskov, A.; Haas, F.; Hannappel, J.; von Harrach, D.; Hasegawa, T.; Heckmann, J.; Hedicke, S.; Heinsius, F.H.; Hermann, R.; Hess, C.; Hinterberger, F.; von Hodenberg, M.; Horikawa, N.; Horikawa, S.; d'Hose, N.; Ilgner, C.; Ioukaev, A.I.; Ishimoto, S.; Ivanov, O.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Janata, A.; Jasinski, P.; Joosten, R.; Jouravlev, N.I.; Kabuss, E.; Kang, D.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu.A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koblitz, S.; Koivuniemi, J.H.; Kolosov, V.N.; Komissarov, E.V.; Kondo, K.; Konigsmann, K.; Konorov, I.; Konstantinov, V.F.; Korentchenko, A.S.; Korzenev, A.; Kotzinian, A.M.; Koutchinski, N.A.; Kouznetsov, O.; Kral, A.; Kravchuk, N.P.; Kroumchtein, Z.V.; Kuhn, R.; Kunne, F.; Kurek, K.; Ladygin, M.E.; Lamanna, M.; Le Goff, J.M.; Lednev, A.A.; Lehmann, A.; Levorato, S.; Lichtenstadt, J.; Liska, T.; Ludwig, I.; Maggiora, A.; Maggiora, M.; Magnon, A.; Mallot, G.K.; Mann, A.; Marchand, C.; Marroncle, J.; Martin, A.; Marzec, J.; Massmann, F.; Matsuda, T.; Maximov, A.N.; Meyer, W.; Mielech, A.; Mikhailov, Yu.V.; Moinester, M.A.; Mutter, A.; Nagaytsev, A.; Nagel, T.; Nahle, O.; Nassalski, J.; Neliba, S.; Nerling, F.; Neubert, S.; Neyret, D.P.; Nikolaenko, V.I.; Nikolaev, K.; Olshevsky, A.G.; Ostrick, M.; Padee, A.; Pagano, P.; Panebianco, S.; Panknin, R.; Panzieri, D.; Paul, S.; Pawlukiewicz-Kaminska, B.; Peshekhonov, D.V.; Peshekhonov, V.D.; Piragino, G.; Platchkov, S.; Pochodzalla, J.; Polak, J.; Polyakov, V.A.; Pretz, J.; Procureur, S.; Quintans, C.; Rajotte, J.F.; Ramos, S.; Rapatsky, V.; Reicherz, G.; Reggiani, D.; Richter, A.; Robinet, F.; Rocco, E.; Rondio, E.; Rozhdestvensky, A.M.; Ryabchikov, D.I.; Samoylenko, V.D.; Sandacz, A.; Santos, H.; Sapozhnikov, M.G.; Sarkar, S.; Savin, I.A.; Schiavon, P.; Schill, C.; Schmitt, L.; Schonmeier, P.; Schroder, W.; Shevchenko, O.Yu.; Siebert, H.W.; Silva, L.; Sinha, L.; Sissakian, A.N.; Slunecka, M.; Smirnov, G.I.; Sosio, S.; Sozzi, F.; Srnka, A.; Stinzing, F.; Stolarski, M.; Sugonyaev, V.P.; Sulc, M.; Sulej, R.; Tchalishev, V.V.; Tessaro, S.; Tessarotto, F.; Teufel, A.; Tkatchev, L.G.; Venugopal, G.; Virius, M.; Vlassov, N.V.; Vossen, A.; Webb, R.; Weise, E.; Weitzel, Q.; Windmolders, R.; Wirth, S.; Wislicki, W.; Wollny, H.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Zhao, J.; Ziegler, R.; Zvyagin, A.

    2008-01-01

    The semi-inclusive difference asymmetry A^{h+ - h-} for hadrons of opposite charge has been measured by the COMPASS experiment at CERN. The data were collected in the years 2002-2004 using a 160 GeV polarised muon beam scattered off a large polarised 6-LiD target and cover the range 0.006 < x < 0.7 and 1 < Q^2 < 100 (GeV/c)^2. In leading order QCD (LO) the asymmetry A_d^{h+ - h-} measures the valence quark polarisation and provides an evaluation of the first moment of Delta u_v + Delta d_v which is found to be equal to 0.40 +- 0.07 (stat.) +- 0.05 (syst.) over the measured range of x at Q^2 = 10 (GeV/c)^2. When combined with the first moment of g_1^d previously measured on the same data, this result favours a non-symmetric polarisation of light quarks Delta u-bar = -Delta d-bar at a confidence level of two standard deviations, in contrast to the often assumed symmetric scenario Delta u-bar = Delta d-bar = Delta s-bar = Delta s.

  1. Identification of different magnetic modes in CsFeCl{sub 3} by polarisation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Dorner, B [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France); Toperverg, B [St. Petersburg Nuclear Physics Inst., St. Petersburg (Russian Federation); Baehr, M [Hahn-Meitner-Institut Berlin GmbH (Germany); Petitgrand, D [Laboratoire Leon Brillouin (LLB) - Centre d` Etudes de Saclay, 91 - Gif-sur-Yvette (France)

    1996-11-01

    CsFeCl{sub 3} is a quasi 1D magnetic system with a singlet groundstate. The Fe{sup 2+} ion has an effective spin S=1. Experimental results in a magnetic field applied perpendicular to the anisotropy axis show that the excited states (doubly degenerate in zero field) split and shift to higher frequencies with increasing field. The split of the high frequency modes is very small compared to the instrumental resolution. Only polarisation analysis of inelastic neutron scattering made it possible to observe the splitting everywhere in reciprocal space. The frequency shift of the two modes with field is different such that a mode crossing appears for fields below about 4 Tesla. (author) 9 figs., 1 tab., 7 refs.

  2. Identification of different magnetic modes in CsFeCl3 by polarisation analysis

    International Nuclear Information System (INIS)

    Dorner, B.; Toperverg, B.; Baehr, M.; Petitgrand, D.

    1996-01-01

    CsFeCl 3 is a quasi 1D magnetic system with a singlet groundstate. The Fe 2+ ion has an effective spin S=1. Experimental results in a magnetic field applied perpendicular to the anisotropy axis show that the excited states (doubly degenerate in zero field) split and shift to higher frequencies with increasing field. The split of the high frequency modes is very small compared to the instrumental resolution. Only polarisation analysis of inelastic neutron scattering made it possible to observe the splitting everywhere in reciprocal space. The frequency shift of the two modes with field is different such that a mode crossing appears for fields below about 4 Tesla. (author) 9 figs., 1 tab., 7 refs

  3. Cross-polarisation discrimination-induced interference in dual-polarised high-capacity satellite communication systems

    Directory of Open Access Journals (Sweden)

    Abdulkareem Sarki Karasuwa

    2016-05-01

    Full Text Available The design of spectrally-efficient, high-throughput satellite (HTS systems with capacity approaching one terabit per second requires operating at Ka-band frequencies and above, where there are several gigahertz of allocated radio spectrum, using multiple spot beams with dual orthogonal polarisation mode. At these high frequencies, rain attenuation poses a major obstacle to the design of high-availability satellite links which are needed for the realisation of ubiquitous broadband multimedia communication services including high-speed Internet access at rural and remote locations. Furthermore, depolarisation-induced interference in such systems could have a performance-limiting impact if a co-channel cross-polar signal combines with system noise to drive the carrier-to-noise-plus-interference ratio (CNIR below an acceptable threshold. This paper employs real measurement data to investigate the impact of depolarisation-induced interference on dual-polarised HTS systems for temperate and tropical climatic regions. Scenarios that cause significant system performance degradation are analysed, including the effects of signal frequency, antenna size, and regional rainfall rate. The impact of depolarisation on system performance is quantified by the reductions in the CNIR and link availability of a dual-polarised system when compared with those of a similarly-dimensioned single-polarised system.

  4. The OSIRIS diffractometer and polarisation analysis spectrometer at ISIS. New developments and 3He spin-filter polarisation analysis

    International Nuclear Information System (INIS)

    Andersen, Ken H.; Marero, David Martin y; Barlow, Michael J.

    2001-01-01

    OSIRIS combines a long-wavelength powder diffractometer with a polarisation analysis backscattering spectrometer. The diffractometer can access wavelengths up to 70 A with a resolution of better than 1% Δd/d. The very high counting-rate at shorter wavelengths is ideal for in-situ, real-time and parametric experiments. The spectroscopy section incorporates an array of graphite crystals arranged in near-backscattering to give a high counting rate with 25 μeV energy resolution. The incident beam is polarised using a supermirror bender and the scattered beam is polarisation-analysed by a 3 He spin-filter in the process of being constructed. The spin-filter system consists of a fibre laser, a peristaltic pump and a wide-angle banana-shaped quartz cell in a continuous-flow setup. The scattered beam passes twice through the spin-filter cell, thus doubling the optical path length in the cell. The aim is to achieve 70% nuclear polarisation with no variation in time. (author)

  5. Neutron spin precession in samples of polarised nuclei and neutron spin phase imaging

    International Nuclear Information System (INIS)

    Piegsa, Florian Michael

    2009-01-01

    The doublet neutron-deuteron (nd) scattering length b 2,d , which is at present only known with an accuracy of 5%, is particularly well suited to fix three-body forces in novel effective field theories at low energies. The understanding of such few-nucleon systems is essential, e.g. for predictions of element abundances in the big-bang and stellar fusion. b 2,d can be obtained via a linear combination of the spin-independent nd scattering length b c,d and the spin-dependent one, b i,d . The aim of this thesis was to perform a high-accuracy measurement of the latter to improve the relative accuracy of b 2,d below 1%. The experiment was performed at the fundamental neutron physics beam line FUNSPIN at the Paul Scherrer Institute in Switzerland. It utilises the effect that the spin of a neutron passing through a target with polarised nuclei performs a pseudomagnetic precession proportional to the spin-dependent scattering length of the nuclei. An ideal method to measure this precession angle very accurately is Ramsey's atomic beam technique, adapted to neutrons. The most crucial part of the experimental setup is the so-called frozen spin target, which consists of a specially designed dilution refrigerator and contains a sample with dynamically polarised nuclear spins. The polarisation of the sample is determined by nuclear magnetic resonance (NMR) techniques. It turned out that the relaxation of the nuclear spins during the necessary ''cross-calibration'' of the two employed NMR systems is ultimately limiting the achievable accuracy of b i,d . During the extensive use of the Ramsey resonance method in the neutron-deuteron experiment, an idea emerged that the applied technique could be exploited in a completely different context, namely polarised neutron radiography. Hence, the second part of the thesis covers the development of a novel neutron radiography technique, based on the spin-dependent interaction of the neutron with ferromagnetic samples and magnetic fields

  6. Neutron spin precession in samples of polarised nuclei and neutron spin phase imaging

    Energy Technology Data Exchange (ETDEWEB)

    Piegsa, Florian Michael

    2009-07-09

    The doublet neutron-deuteron (nd) scattering length b{sub 2,d}, which is at present only known with an accuracy of 5%, is particularly well suited to fix three-body forces in novel effective field theories at low energies. The understanding of such few-nucleon systems is essential, e.g. for predictions of element abundances in the big-bang and stellar fusion. b{sub 2,d} can be obtained via a linear combination of the spin-independent nd scattering length b{sub c,d} and the spin-dependent one, b{sub i,d}. The aim of this thesis was to perform a high-accuracy measurement of the latter to improve the relative accuracy of b{sub 2,d} below 1%. The experiment was performed at the fundamental neutron physics beam line FUNSPIN at the Paul Scherrer Institute in Switzerland. It utilises the effect that the spin of a neutron passing through a target with polarised nuclei performs a pseudomagnetic precession proportional to the spin-dependent scattering length of the nuclei. An ideal method to measure this precession angle very accurately is Ramsey's atomic beam technique, adapted to neutrons. The most crucial part of the experimental setup is the so-called frozen spin target, which consists of a specially designed dilution refrigerator and contains a sample with dynamically polarised nuclear spins. The polarisation of the sample is determined by nuclear magnetic resonance (NMR) techniques. It turned out that the relaxation of the nuclear spins during the necessary ''cross-calibration'' of the two employed NMR systems is ultimately limiting the achievable accuracy of b{sub i,d}. During the extensive use of the Ramsey resonance method in the neutron-deuteron experiment, an idea emerged that the applied technique could be exploited in a completely different context, namely polarised neutron radiography. Hence, the second part of the thesis covers the development of a novel neutron radiography technique, based on the spin-dependent interaction of the

  7. Resonant parametric interference effect in spontaneous bremsstrahlung of an electron in the field of a nucleus and two pulsed laser waves

    Science.gov (United States)

    Lebed', A. A.; Padusenko, E. A.; Roshchupkin, S. P.; Dubov, V. V.

    2018-04-01

    Electron-nucleus bremsstrahlung in the field of two moderately strong pulsed laser waves in the case of incommensurate frequencies is theoretically studied under resonant conditions. The process is studied in detail in a special kinematic region, where stimulated processes with correlated emission and absorption of photons of the first and second waves become predominant (parametric interference effect). The availability of this region is caused by interference of the first and second laser waves. The correspondence between the emission angle and the final-electron energy is established in this interference kinematic. In this case, the cross-sectional properties are determined by the multiphoton quantum interference parameter, which is proportional to the product of intensities of the first and second waves. The resonant differential cross section of electron-nucleus spontaneous bremsstrahlung with simultaneous registration of both emission angles of the spontaneous photon and the scattered electron can exceed by four or five orders of magnitude the corresponding cross section in the absence of an external field. It was shown for nonrelativistic electrons that the resonant cross section of the studied process in the field of two pulsed laser waves within the interference region in two order of magnitude may exceed corresponding cross sections at other scattering kinematics. The obtained results may be experimentally verified, for example, by scientific facilities at sources of pulsed laser radiation (such as SLAC, FAIR, XFEL, ELI).

  8. Method for determination of the polarisation nonreciprocity in a fibre ring interferometer

    International Nuclear Information System (INIS)

    Andronova, Irina A; Gelikonov, V M; Gelikonov, G V

    2000-01-01

    A method is proposed for observation of the polarisation nonreciprocity of fibre ring interferometers (FRIs) by placing a rotating polariser at the output of an interferometer ahead of a photodetector. It is demonstrated theoretically and experimentally that the absence of a signal for any position of the transmission axis of the polariser at the FRI output is a criterion of the absence of the polarisation nonreciprocity. It is suggested that the coaxial alignment of the anisotropic FRI components be monitored during assembly to ensure the polarisation nonreciprocity on the basis of the absence of a signal at the output of a rotating polariser. It is also shown that, when the conditions for the polarisation nonreciprocity are fulfilled, the signal from the output of a beam splitter located flush against the fibre loop output carries information about the phase characteristics of the beam splitter. (laser gyroscopes)

  9. Method and apparatus for measuring weak magnetic fields

    DEFF Research Database (Denmark)

    1995-01-01

    When measuring weak magnetic fields, a container containing a medium, such as a solution containing a stable radical, is placed in a polarising magnetic field, which is essentially at right angles to the field to be measured. The polarising field is interrupted rapidly, the interruption being...

  10. One Country, Two Polarised Audiences: Estonia and the Deficiency of the Audiovisual Media Services Directive

    Directory of Open Access Journals (Sweden)

    Andres Jõesaar

    2015-12-01

    Full Text Available This article argues that until recent times, the Estonian media policy has mainly been interpreted as an economic issue and it did not account for the strategic need to build a comprehensive media field to serve all groups in society. This has happened despite the fact the Estonian media policy is in line with the European Union (EU media policy, which should ensure freedom of information, diversity of opinion and media pluralism. Findings of the Estonian case study show that despite these noble aims, Estonia has two radically different information fields: one for Estonian speaking audiences and one for Russian speakers. Events in Ukraine have added to the democratic media policy paradigm a question of national security. Now it is a challenge for the policy makers to unite polarised media fields and how to minimise the impact of Russian propaganda. On the EU level, one supportive measure could be a revision of the Audiovisual Media Service Directive.

  11. Metastability in spin polarised Fermi gases and quasiparticle decays

    DEFF Research Database (Denmark)

    Sadeghzadeh, Kayvan; Bruun, Georg; Lobo, Carlos

    2011-01-01

    We investigate the metastability associated with the first order transition from normal to superfluid phases in the phase diagram of two-component polarised Fermi gases.We begin by detailing the dominant decay processes of single quasiparticles.Having determined the momentum thresholds of each...... the interaction strength at which a polarised phase of molecules becomes the groundstate, to the one at which the single quasiparticle groundstate changes character from polaronic to molecular. Our argument in terms of a Fermi sea of polarons naturally suggests their use as an experimental probe. We propose...... experiments to observe the threshold of the predicted region of metastability, the interaction strength at which the quasiparticle groundstate changes character, and the decay rate of polarons....

  12. Constraining new resonant physics with top spin polarisation information

    Energy Technology Data Exchange (ETDEWEB)

    Englert, Christoph; Nordstroem, Karl [University of Glasgow, SUPA, School of Physics and Astronomy, Glasgow (United Kingdom); Ferrando, James [DESY Hamburg, Hamburg (Germany)

    2017-06-15

    We provide a comprehensive analysis of the power of including top quark-polarisation information to kinematically challenging top pair resonance searches, for which ATLAS and CMS start losing sensitivity. Following the general modelling and analysis strategies pursued by the experiments, we analyse the semi-leptonic and the di-lepton channels and show that including polarisation information can lead to large improvements in the limit setting procedures with large data sets. This will allow us to set stronger limits for parameter choices where sensitivity from the invariant mass of the top pair is not sufficient. This highlights the importance of spin observables as part of a more comprehensive set of observables to gain sensitivity to BSM resonance searches. (orig.)

  13. Measurement of the tau polarisation at the Z resonance

    Science.gov (United States)

    Buskulic, D.; Decamp, D.; Goy, C.; Lees, J.-P.; Minard, M.-N.; Mours, B.; Pietrzyk, B.; Alemany, R.; Ariztizabal, F.; Comas, P.; Crespo, J. M.; Delfino, M.; Fenandez, E.; Fernandez-Bosman, M.; Gaitan, V.; Garrido, Ll.; Mattison, T.; Pacheco, A.; Padilla, C.; Pascual, A.; Creanza, D.; de Palma, M.; Farilla, A.; Iaselli, G.; Maggi, G.; Maggi, M.; Natali, S.; Nuzzo, S.; Quattromini, M.; Ranieri, A.; Raso, G.; Romano, F.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Zito, G.; Chai, Y.; Hu, H.; Huang, D.; Huang, X.; Lin, J.; Wang, T.; Xie, Y.; Xu, D.; Xu, R.; Zhang, J.; Zhao, W.; Bauerdick, L. A. T.; Blucher, E.; Bonvicini, G.; Boudreau, J.; Casper, D.; Drevermann, H.; Forty, R. W.; Ganis, G.; Gay, C.; Hagelberg, R.; Harvey, J.; Haywood, S.; Hilgart, J.; Jacobsen, R.; Jost, B.; Knobloch, J.; Lehraus, I.; Lohse, T.; Lusiani, A.; Martinez, M.; Mato, P.; Meinhard, H.; Minten, A.; Miotto, A.; Miquel, R.; Moser, H.-G.; Palazzi, P.; Perlas, J. A.; Pusztaszeri, J.-F.; Ranjard, F.; Redlinger, G.; Rolandi, L.; Rothberg, J.; Ruan, T.; Saich, M.; Schlatter, D.; Schmelling, M.; Sefkow, F.; Tejessy, W.; Wachsmuth, H.; Wiedenmann, W.; Wildish, T.; Witzeling, W.; Wotschack, J.; Ajaltouni, Z.; Badaud, F.; Bardadin-Otwinowska, M.; El Fellous, R.; Falvard, A.; Gay, P.; Guicheney, C.; Henrard, P.; Jousset, J.; Michel, B.; Montret, J.-C.; Pallin, D.; Perret, P.; Podlyski, F.; Proriol, J.; Prulhière, F.; Saadi, F.; Fearnley, T.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Møllerud, R.; Nilsson, B. S.; Candlin, D. J.; Parsons, M. I.; Veitch, E.; Moneta, L.; Parrini, G.; Corden, M.; Georgiopoulos, C.; Ikeda, M.; Lannutti, J.; Levinthal, D.; Mermikides, M.; Sawyer, L.; Wasserbaech, S.; Antonelli, A.; Baldini, R.; Bencivenni, G.; Bologna, G.; Bossi, F.; Campana, P.; Capon, G.; Cerutti, F.; Chiarella, V.; D'Ettorre-Piazzoli, B.; Felici, G.; Laurelli, P.; Mannocchi, G.; Murtas, F.; Murtas, G. P.; Passalacqua, L.; Pepe-Altarelli, M.; Picchi, P.; Colrain, P.; Ten Have, I.; Lynch, J. G.; Maitland, W.; Morton, W. T.; Raine, C.; Reeves, P.; Scarr, J. M.; Smith, K.; Smith, M. G.; Thompson, A. S.; Turnbull, R. M.; Brandl, B.; Braun, O.; Geweniger, C.; Hanke, P.; Hepp, V.; Kluge, E. E.; Maumary, Y.; Putzer, A.; Rensch, B.; Stahl, A.; Tittel, K.; Wunsch, M.; Belk, A. T.; Beuselinck, R.; Binnie, D. M.; Cameron, W.; Cattaneo, M.; Colling, D. J.; Dornan, P. J.; Dugeay, S.; Greene, A. M.; Hassaed, J. F.; Lieske, N. M.; Nash, J.; Payne, D. G.; Phillips, M. J.; Sedgbeer, J. K.; Tomalin, I. R.; Wright, A. G.; Girtler, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Bowdery, C. K.; Brodbeck, T. J.; Finch, A. J.; Foster, F.; Hughes, G.; Jackson, D.; Keemer, N. R.; Nuttall, M.; Patel, A.; Sloan, T.; Snow, S. W.; Whelan, E. P.; Efthymiopoulos, I.; Kyriakis, A.; Simopoulou, E.; Vayaki, A.; Zachariadou, K.; Badier, J.; Blondel, A.; Bonneaud, G.; Brient, J. C.; Fouque, G.; Orteu, S.; Rougé, A.; Rumpf, M.; Tanaka, R.; Verderi, M.; Videau, H.; Adlung, S.; Assmann, R.; Bauer, C.; Blum, W.; Brown, D.; Cattaneo, P.; Dehning, B.; Dietl, H.; Dydak, F.; Frank, M.; Halley, A. W.; Lauber, J.; Lütjens, G.; Lutz, G.; Männer, W.; Richter, R.; Rotscheidt, H.; Schröder, J.; Schwarz, A. S.; Settles, R.; Seywerd, H.; Stierlin, U.; Stiegler, U.; Denis, R. St.; Wolf, G.; Boucrot, J.; Callot, O.; Cordier, A.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, Ph.; Jaffe, D. E.; Janot, P.; Kim, D. W.; Le Diberder, F.; Lefrançois, J.; Lutz, A.-M.; Schune, M.-H.; Veillet, J.-J.; Videau, I.; Zhang, Z.; Abbaneo, D.; Bagliesi, G.; Batignani, G.; Bosisio, L.; Bottigli, U.; Bozzi, C.; Calderini, G.; Carpinelli, M.; Ciocci, M. A.; Dell'Orso, R.; Ferrante, I.; Fidecaro, F.; Foa, L.; Focardi, E.; Forti, F.; Giassi, A.; Giorgi, M. A.; Gregorio, A.; Ligabue, F.; Mannelli, E. B.; Marrocchesi, P. S.; Messineo, A.; Palla, F.; Rizzo, G.; Sanguinetti, G.; Spagnolo, P.; Steinberger, J.; Tenchini, R.; Tonelli, G.; Triggiani, G.; Vannini, C.; Venturi, A.; Verdini, P. G.; Walsh, J.; Betteridge, A. P.; Carter, J. M.; Green, M. G.; March, P. V.; Mir, Ll. M.; Medcalf, T.; Quazi, I. S.; Strong, J. A.; West, L. R.; Botterill, D. R.; Clifft, R. W.; Edgecock, T. R.; Edwards, M.; Fisher, S. M.; Jones, T. J.; Norton, P. R.; Salmon, D. P.; Thompson, J. C.; Kleinknecht, K.; Raab, J.; Renk, B.; Sander, H.-G.; Schmidt, H.; Steeg, F.; Walther, S. M.; Wanke, R.; Wolf, B.; Aubert, J.-J.; Bencheikh, A. M.; Benchouk, C.; Bonissent, A.; Carr, J.; Coyle, P.; Drinkard, J.; Etienne, F.; Nicod, D.; Papalexiou, S.; Payre, P.; Roos, L.; Rousseau, D.; Schwemling, P.; Talby, M.; Bloch-Devaux, B.; Colas, P.; Duarte, H.; Kozanecki, W.; Lançon, E.; Lemaire, M. C.; Locci, E.; Perez, P.; Perrier, F.; Rander, J.; Renardy, J.-F.; Rosowsky, A.; Roussarie, A.; Schuller, J.-P.; Schwindling, J.; Si Mohand, D.; Vallage, B.; Johnson, R. P.; Litke, A. M.; Taylor, G.; Wear, J.; Ashman, J. G.; Babbage, W.; Booth, C. N.; Buttar, C.; Carney, R. E.; Cartwright, S.; Combley, F.; Hatfield, F.; Thompson, L. F.; Barberio, E.; Böhrer, A.; Brandt, S.; Cowan, G.; Grupen, C.; Lutters, G.; Rivera, F.; Schäfer, U.; Della Marina, R.; Giannini, G.; Gobbo, B.; Ragusa, F.; Bellantoni, L.; Chen, W.; Cinabro, D.; Conway, J. S.; Cowen, D. F.; Feng, Z.; Ferguson, D. P. S.; Gao, Y. S.; Grahl, J.; Harton, J. L.; Jared, R. C.; Leclaire, B. W.; Lishka, C.; Pan, Y. B.; Pater, J. R.; Saadi, Y.; Schmitt, M.; Sharma, V.; Shi, Z. H.; Walsh, A. M.; Weber, F. V.; Wu, Sau Lan; Wu, X.; Zheng, M.; Zobernig, G.

    1993-09-01

    Using 18.8 pb-1 of data collected in 1990 and 1991, ALEPH has measured the tau polarisation in the decay modes τ→ ev bar v, τ→μ v bar v, τ→πν, τ→ρν and τ→ a 1ν, using both the individual tau decay kinematics and the event acollinearity. The measurement of the tau polarisation as a function of the production polar angle yields the two parameters A τ and A e , where A l =2 g {/v l } g {/A l }/( g {/v l })2+( g {/A l })2] The results A τ=0.143±0.023 and A e =0.120±0.026 are consistent with the hypothesis of electron-tau universality. Assuming universality yields a measurement of the effective weak mixing angle sin2θ{/w eff}=0.2332±0.0022.

  14. Spontaneous deregulation

    NARCIS (Netherlands)

    Edelman, Benjamin; Geradin, Damien

    Platform businesses such as Airbnb and Uber have risen to success partly by sidestepping laws and regulations that encumber their traditional competitors. Such rule flouting is what the authors call “spontaneous private deregulation,” and it’s happening in a growing number of industries. The authors

  15. Definition of spontaneous reconnection

    International Nuclear Information System (INIS)

    Schindler, K.

    1984-01-01

    The author discusses his view of driven versus spontaneous. There is a close link between ''spontaneous'' and ''instability.'' One of the prominent examples for instability is the thermal convection instability. Just to remind you, if you heat a fluid layer from below, it takes a certain Rayleigh number to make it unstable. Beyond the onset point you find qualitatively new features. That is called ''spontaneous,'' and this is a bit more than semantics. It's a new qualitative property that appears and it is spontaneous although we have an energy flux through the system. It's a misconception, to call this ''driven'' pointing at the energy flux through it. Of course, the convection would not exist without this energy flux. But what makes it ''spontaneous'' is that without any particular external signal, a new qualitative feature appears. And this is what is called an ''instability'' and ''spontaneous.'' From these considerations the author got a little reassured of what distinction should be made in the field of the magnetosphere. If we have a smooth energy transport into the magnetosphere and suddenly we have this qualitatively new feature (change of B-topology) coming up; then, using this terminology we don't have a choice other than calling this spontaneous or unstable, if you like. If we ''tell'' the system where it should make its neutral line and where it should make its plasmoids, then, it is driven. And this provides a very clear-cut observational distinction. The author emphasizes the difference he sees is a qualitative difference, not only a quantitative one

  16. A Model of Polarisation Rotations in Blazars from Kink Instabilities in Relativistic Jets

    Directory of Open Access Journals (Sweden)

    Krzysztof Nalewajko

    2017-10-01

    Full Text Available This paper presents a simple model of polarisation rotation in optically thin relativistic jets of blazars. The model is based on the development of helical (kink mode of current-driven instability. A possible explanation is suggested for the observational connection between polarisation rotations and optical/gamma-ray flares in blazars, if the current-driven modes are triggered by secular increases of the total jet power. The importance of intrinsic depolarisation in limiting the amplitude of coherent polarisation rotations is demonstrated. The polarisation rotation amplitude is thus very sensitive to the viewing angle, which appears to be inconsistent with the observational estimates of viewing angles in blazars showing polarisation rotations. Overall, there are serious obstacles to explaining large-amplitude polarisation rotations in blazars in terms of current-driven kink modes.

  17. Spontaneous and field-induced phase transitions in TbFe.sub.5./sub.Al.sub.7./sub..

    Czech Academy of Sciences Publication Activity Database

    Gorbunov, Denis; Yasin, S.; Andreev, Alexander V.; Mushnikov, N. V.; Skourski, Y.; Zherlitsyn, S.; Wosnitza, J.

    2014-01-01

    Roč. 535, Sep (2014), 56-63 ISSN 0304-8853 R&D Projects: GA ČR GAP204/12/0150 Grant - others:AVČR(CZ) M100101203 Institutional support: RVO:68378271 Keywords : rare-earth intermetallics * ferrimagnetism * magnetic anisotropy * spin-reorientation transition * high magnetic fields * field-induced transition Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.970, year: 2014

  18. Spontaneous Pneumothorax

    Directory of Open Access Journals (Sweden)

    John Costumbrado

    2017-09-01

    Full Text Available History of present illness: A 16-year-old male with asthma was brought to the emergency department by his parents for increasing right-sided chest pain associated with cough and mild dyspnea over the past week. Albuterol inhaler did not provide relief. He denied recent trauma, fever, sweats, and chills. The patient’s vitals and oxygen saturations were stable. Physical exam revealed a tall, slender body habitus with no signs of chest wall injuries. Bilateral breath sounds were present, but slightly diminished on the right. A chest radiograph was ordered to determine the etiology of the patient’s symptoms. Significant findings: Initial chest radiograph showed a 50% right-sided pneumothorax with no mediastinal shift, which can be identified by the sharp line representing the pleural lung edge (see arrows and lack of peripheral lung markings extending to the chest wall. While difficult to accurately estimate volume from a two-dimensional image, a 2 cm pneumothorax seen on chest radiograph correlates to approximately 50% volume.1 The patient underwent insertion of a pigtail pleural drain on the right and repeat chest radiograph showed resolution of previously seen pneumothorax. Ultimately the pigtail drain was removed and chest radiograph showed clear lung fields without evidence of residual pneumothorax or pleural effusion. Discussion: Pneumothorax is characterized by air between the lungs and the chest wall.2 Spontaneous pneumothorax (SP occurs when the pneumothorax is not due to trauma or any discernable etiology. 3 SP is multifactorial and may be associated with subpleural blebs, bullae, and other connective tissue changes that predispose the lungs to leak air into the pleural space.4 SP can be further subdivided into primary (no history of underlying lung disease or secondary (history of chronic obstructive pulmonary disease, tuberculosis, cystic fibrosis, lung malignancy, etc..2 It is estimated that the incidence of SP among US pediatric

  19. Scalar field dark matter with spontaneous symmetry breaking and the 3.5 keV line

    Science.gov (United States)

    Cosme, Catarina; Rosa, João G.; Bertolami, O.

    2018-06-01

    We show that the present dark matter abundance can be accounted for by an oscillating scalar field that acquires both mass and a non-zero expectation value from interactions with the Higgs field. The dark matter scalar field can be sufficiently heavy during inflation, due to a non-minimal coupling to gravity, so as to avoid the generation of large isocurvature modes in the CMB anisotropies spectrum. The field begins oscillating after reheating, behaving as radiation until the electroweak phase transition and afterwards as non-relativistic matter. The scalar field becomes unstable, although sufficiently long-lived to account for dark matter, due to mass mixing with the Higgs boson, decaying mainly into photon pairs for masses below the MeV scale. In particular, for a mass of ∼7 keV, which is effectively the only free parameter, the model predicts a dark matter lifetime compatible with the recent galactic and extragalactic observations of a 3.5 keV X-ray line.

  20. Spontaneous restoration of target vegetation in old-fields in a central European landscape: a repeated analysis after three decades

    Czech Academy of Sciences Publication Activity Database

    Jírová, Alena; Klaudisová, A.; Prach, Karel

    2012-01-01

    Roč. 15, č. 2 (2012), 245-252 ISSN 1402-2001 R&D Projects: GA ČR(CZ) GAP505/11/0256 Institutional research plan: CEZ:AV0Z60050516 Institutional support: RVO:67985939 Keywords : succession * vegetation * abandoned fields Subject RIV: EH - Ecology, Behaviour Impact factor: 2.263, year: 2012

  1. Phase noise cancellation in polarisation-maintaining fibre links

    Science.gov (United States)

    Rauf, B.; Vélez López, M. C.; Thoumany, P.; Pizzocaro, M.; Calonico, D.

    2018-03-01

    The distribution of ultra-narrow linewidth laser radiation is an integral part of many challenging metrological applications. Changes in the optical pathlength induced by environmental disturbances compromise the stability and accuracy of optical fibre networks distributing the laser light and call for active phase noise cancellation. Here we present a laboratory scale optical (at 578 nm) fibre network featuring all polarisation maintaining fibres in a setup with low optical powers available and tracking voltage-controlled oscillators implemented. The stability and accuracy of this system reach performance levels below 1 × 10-19 after 10 000 s of averaging.

  2. Polarization of Bremsstrahlung; Polarisation du rayonnement de freinage

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-07-01

    The numerical results for the polarization of Bremsstrahlung are presented. The multiple scattering of electrons in the target is taken into account. The angular-and photon energy dependences are seen on the curves for an incident 25 MeV electron energy. (Author) [French] Le taux de polarisation d'un spectre de rayonnement de freinage est calcule pour une cible d'epaisseur finie en tenant compte de la diffusion multiple des electrons dans la cible. Les courbes sont tracees pour les electrons incidents d'energie 25 MeV, pour differentes energies de photons, et a differents angles. (auteur)

  3. Top Polarisation in H-t and Wt production

    International Nuclear Information System (INIS)

    Godbole, R.M.; Hartgring, L.; Niessen, I.; White, C.D.

    2012-01-01

    We consider laboratory frame observables (like the azimuthal angle between the top quark and its decay lepton or the polar angle between the top quark and leptonic directions) obtained from leptonic decay products of top quarks produced in association with a charged Higgs or W boson. These are robust against QCD corrections to top quark decay, and can be used to pin down the parameter space of a charged Higgs boson, or reduce backgrounds in H - t and (Standard Model) Wt production. Polarisation information can efficiently be used to distinguish single top quark production processes from their backgrounds, as well as to pin down the parameters of a charged Higgs boson model

  4. Orientation, alignment and polarisation in electron-helium collisions

    International Nuclear Information System (INIS)

    Beijers, J.P.M.

    1987-01-01

    In this thesis electron-photon coincidence experiments to study the excitation of helium by electron impact are updated. This is achieved by cross firing a well collimated and mono-energetic electron beam with a thermal helium beam and measuring the angular and/or polarisation distribution of the decay photons in coincidence with the inelastically scattered electrons. In this way target parameters are determined for the 2 1 P, 3 1 P, 3 1 D and 3 3 P states of helium. (Auth.)

  5. Spontaneously generated field theories, zero-center modules, colored singletons and the virtues of N = 6 supergravity

    International Nuclear Information System (INIS)

    Flato, M.; Fronsdal, C.

    1986-01-01

    Attention is called to an interesting property of the space of one-particle states in some especially important massless field theories: the appearance of a one-particle ghost with zero energy. It appears in conformal as well as de Sitter electrodynamics, in the physical sectors of the field mode representations of the respective symmetry groups. It appears again in super de Sitter electrodynamics based on the superalgebra osp(4/1) and in super conformal electrodynamics based on su(2,2/1). The authors next construct two families of extended super QED, incorporating this property, based on osp(4/N) and on su(2,2/N). There is precisely one osp(4/N) theory and one su(2,2/N) theory of this type for each value of N. The osp(4/6) theory is the same as N = 6 extended supergravity, this is the only one among this family of osp(4/N) theories in which the highest spin is 2. All the one particle states are massless, and in the osp(4/N) theories they can be interpreted as states of two colored singletons. The authors also critically examine the concept of the Witten index in flat space as well as in de Sitter supersymmetric field theories. (Auth.)

  6. Constraining ALPs with linear and circular polarisation measurements of quasar light

    International Nuclear Information System (INIS)

    Payez, Alexandre

    2013-09-01

    We discuss the constraints derived on the mixing of photons with light pseudoscalars using the distributions of good-quality linear and circular polarisation measurements of light from the least polarised classes of quasars. We also provide the dependence of our limit on the average electron density in the local supercluster for nearly massless particles.

  7. Constraining ALPs with linear and circular polarisation measurements of quasar light

    Energy Technology Data Exchange (ETDEWEB)

    Payez, Alexandre [Liege Univ. (Belgium). IFPA Group; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-09-15

    We discuss the constraints derived on the mixing of photons with light pseudoscalars using the distributions of good-quality linear and circular polarisation measurements of light from the least polarised classes of quasars. We also provide the dependence of our limit on the average electron density in the local supercluster for nearly massless particles.

  8. Polarisation analysis of elastic neutron scattering using a filter spectrometer on a pulsed source

    International Nuclear Information System (INIS)

    Mayers, J.; Williams, W.G.

    1981-05-01

    The experimental and theoretical aspects of the polarisation analysis technique in elastic neutron scattering are described. An outline design is presented for a filter polarisation analysis spectrometer on the Rutherford Laboratory Spallation Neutron Source and estimates made of its expected count rates and resolution. (author)

  9. Tunable polarisation-maintaining filter based on liquid crystal photonic bandgap fibre

    DEFF Research Database (Denmark)

    Scolari, Lara; Olausson, Christina Bjarnal Thulin; Weirich, Johannes

    2008-01-01

    A tunable and polarisation-maintaining all-in-fibre filter based on a liquid crystal photonic bandgap fibre is demonstrated. Its polarisation extinction ratio reaches 14 dB at 1550 nm wavelength. Its spectral tunability range spans over 250 nm in the temperature range 30–70°C. The measured...

  10. Time-resolved proton polarisation (TPP) images tyrosyl radical sites in bovine liver catalase.

    Science.gov (United States)

    Zimmer, Oliver; Jouve, Hélène M.; Stuhrmann, Heinrich B.

    2017-05-01

    A differentiation between dynamic polarised protons close to tyrosyl radical sites in catalase and those of the bulk is achieved by time-resolved polarised neutron scattering. Three radical sites, all of them being close to the molecular centre and the heme, appear to be equally possible. Among these is tyr-369 the radial site of which had previously been proven by EPR.

  11. Polarisation Control of DFB Fibre Laser Using UV-Induced Birefringent Phase-Shift

    DEFF Research Database (Denmark)

    Philipsen, Jacob Lundgreen; Lauridsen, Vibeke Claudia; Berendt, Martin Ole

    1998-01-01

    The polarisation properties of a distributed feedback (DFB) fibre laser are investigated experimentally. A birefringent phase-shift is induced by side illumination of the centre part of the lasing structure with ultraviolet (UV) light and it is experimentally shown that the birefringence...... of the phase-shift is the dominating effect controlling the polarisation properties of the laser....

  12. High Extinction Ratio In-Fibre Polarisers by Exploiting Tilted Fibre Bragg Grating Structures for Single-Polarisation High-Power Fibre Lasers and Amplifiers

    Science.gov (United States)

    2009-11-01

    maintaining (PM) fibre, utilising polarisation hole-burning ( PHB ) effect to reduce homogeneous linewidth of the EDFL. In our work, we demonstrate a stable...loss filter which will induce some loss to the cavity around its paired attenuation band region, thus imposing PHB effect to the gain medium. The...polarisation-hole-burning ( PHB ) effect to realise multi-wavelength switchable function in proposed fibre ring laser system. In the proposed fibre ring laser

  13. Precision tracking and electromagnetic calorimetry towards a measurement of the pion polarisabilities at COMPASS

    Energy Technology Data Exchange (ETDEWEB)

    Dinkelbach, Anna-Maria Elisabeth

    2010-07-20

    In 2004 the COMPASS experiment at CERN SPS measured soft reactions with a beam of negatively charged pions on various nuclear targets. For this measurement, a silicon micro-strip telescope was installed in the target region. For the first time 5 silicon detector stations were operated simultaneously in the COMPASS experiment. A novel method of time calibration, with a clustering algorithm accordingly adapted, and refined alignment corrections were implemented in the analysis software. The spatial resolution of a silicon detector was determined to be 5 - 14 {mu}m and the time resolution 2 - 3 ns. Combining the time information of all stations, a track time resolution of 530 ps from the silicon telescope could be reached. One of the key points of this experiment was the observation of Primakoff events, namely pions scattering off quasi-real photons in the Coulomb field of a heavy nucleus. The production of real photons corresponds to pion Compton scattering in inverse kinematics which is sensitive to the pion polarisabilities {alpha}{sub {pi}} and {beta}{sub {pi}}. Key ingredient for such measurements is a precise knowledge of the performance of the electromagnetic calorimeter. This includes a study of the instabilities of calorimeter cells and an improved reconstruction algorithm. A data-driven shower model was developed, which was used for a timedependent recalibration of the calorimeter. A new cluster refitting method was used to recover position and energy of clusters containing passive or saturated cells and detects double-hit clusters. The latter are important, as the main background to the Primakoff Compton events stems from neutral pions misinterpreted as single-photon hits. The physics analysis comprised the selection of Primakoff events and the necessary steps to obtain the pionic polarisabilities. The measurement was limited by systematic effects of the apparatus also determined within this thesis. (orig.)

  14. [Spontaneous hypoglycemia].

    Science.gov (United States)

    Ellorhaoui, M; Schultze, W

    1977-01-15

    On the basis of a survey is attempted to describe mode of development, symptomatology, individual forms and the different possibilities of therapy of the spontaneous hypoglycaemias. A particularly broad range was devoted to the cerebral sequelae, since in these cases--according to our experience--on account of simulation of neurologico-psychiatric symptoms at the soonest wrong diagnoses are to be expected. Furthermore, it is attempted to classify the hypoglycemias according to their development, in which cases their incompleteness was evident from the very beginning. The individual forms of appearance are treated according their to significance. Out of the inducible hypoglycaemias a particular attention is devoted to the forms caused by insulin and oral antidiabetics, since these most frequently participate in the development. Finally the author inquires into diagnostic measures for recognition of special forms of hypoglycaemia. In this place the diagnostics of hyperinsulinism conditioned by adenomatosis or tumours of other kinds is of particular importance. Finally conservative and operative possibilities of the therapy of these tumours are discussed,whereby the only recently tested treatment with streptotocin is mentioned.

  15. Polarisation and precise calibration of the LEP beam energy

    CERN Document Server

    Koutchouk, Jean-Pierre

    2002-01-01

    We report in this article on two issues of precision accelerator physics, performed at the LEP collider, that challenged international collaborations. The first result is an increase of the polarisation degree from an almost vanishing natural level to 50%, opening the way to energy calibration by resonant depolarisation. The second result is a systematic and precise determination of the collider centre-of- mass energy correcting for subtle effects such as the azimuthal variation of the beam energy, the magnet temperature, the effects of parasitic earth currents and terrestrial tides. It resulted in an extremely accurate test of the standard model and set significant constraints on the top quark and Higgs masses. (16 refs).

  16. Towards the NNLO evolution of polarised parton distributions

    International Nuclear Information System (INIS)

    Vogt, A.; Vermaseren, J.A.M.

    2008-07-01

    We report on the first calculation of the structure function g 1 in polarised deep-inelastic scattering to the third order in massless perturbative QCD. The calculation follows the dispersive approach already used for the corresponding unpolarised cases of F 2,L , but additionally involves higher tensor integrals and the Dirac matrix γ 5 in D ≠ 4 dimensions. Our results confirm all known two-loop expressions including the coefficient functions of Zijlstra and van Neerven not independently verified before. At three loops we extract the helicity-difference next-to-next-to-leading order (NNLO) quark-quark and gluon-quark splitting functions ΔP qq and ΔP qg . The results exhibit interesting features concerning sum rules and the momentum-fraction limits x → 1 and x → 0. (orig.)

  17. Towards the NNLO evolution of polarised parton distributions

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, A. [Liverpool Univ. (United Kingdom). Dept. of Mathematical Sciences; Moch, S.; Rogal, M. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Vermaseren, J.A.M. [Nationaal Inst. voor Kernfysica en Hoge-Energiefysica (NIKHEF), Amsterdam (Netherlands)

    2008-07-15

    We report on the first calculation of the structure function g{sub 1} in polarised deep-inelastic scattering to the third order in massless perturbative QCD. The calculation follows the dispersive approach already used for the corresponding unpolarised cases of F{sub 2,L}, but additionally involves higher tensor integrals and the Dirac matrix {gamma}{sub 5} in D {ne} 4 dimensions. Our results confirm all known two-loop expressions including the coefficient functions of Zijlstra and van Neerven not independently verified before. At three loops we extract the helicity-difference next-to-next-to-leading order (NNLO) quark-quark and gluon-quark splitting functions {delta}P{sub qq} and {delta}P{sub qg}. The results exhibit interesting features concerning sum rules and the momentum-fraction limits x {yields} 1 and x {yields} 0. (orig.)

  18. Exclusive $\\rho^0$ muoproduction on transversely polarised protons and deuterons

    CERN Document Server

    Adolph, C.; Alexakhin, V.Yu.; Alexandrov, Yu.; Alexeev, G.D.; Amoroso, A.; Antonov, A.A.; Austregesilo, A.; Badelek, B.; Balestra, F.; Barth, J.; Baum, G.; Bedfer, Y.; Bernhard, J.; Bertini, R.; Bettinelli, M.; Bicker, K.; Bieling, J.; Birsa, R.; Bisplinghoff, J.; Bordalo, P.; Bradamante, F.; Braun, C.; Bravar, A.; Bressan, A.; Buchele, M.; Burtin, E.; Capozza, L.; Chiosso, M.; Chung, S.U.; Cicuttin, A.; Crespo, M.L.; Dalla Torre, S.; Das, S.; Dasgupta, S.S.; Dasgupta, S.; Denisov, O.Yu.; Dhara, L.; Donskov, S.V.; Doshita, N.; Duic, V.; Dunnweber, W.; Dziewiecki, M.; Efremov, A.; Elia, C.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Filin, A.; Finger, M.; Finger, M., Jr.; Fischer, H.; Franco, C.; du Fresne von Hohenesche, N.; Friedrich, J.M.; Frolov, V.; Garfagnini, R.; Gautheron, F.; Gavrichtchouk, O.P.; Gerassimov, S.; Geyer, R.; Giorgi, M.; Gnesi, I.; Gobbo, B.; Goertz, S.; Grabmuller, S.; Grasso, A.; Grube, B.; Gushterski, R.; Guskov, A.; Guthorl, T.; Haas, F.; von Harrach, D.; Heinsius, F.H.; Herrmann, F.; Hess, C.; Hinterberger, F.; Horikawa, N.; Hoppner, Ch.; d'Hose, N.; Ishimoto, S.; Ivanov, O.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Jasinski, P.; Jegou, G.; Joosten, R.; Kabuss, E.; Kang, D.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu.A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koblitz, S.; Koivuniemi, J.H.; Kolosov, V.N.; Kondo, K.; Konigsmann, K.; Konorov, I.; Konstantinov, V.F.; Korzenev, A.; Kotzinian, A.M.; Kouznetsov, O.; Kramer, M.; Kroumchtein, Z.V.; Kunne, F.; Kurek, K.; Lauser, L.; Lednev, A.A.; Lehmann, A.; Levorato, S.; Lichtenstadt, J.; Liska, T.; Maggiora, A.; Magnon, A.; Makke, N.; Mallot, G.K.; Mann, A.; Marchand, C.; Martin, A.; Marzec, J.; Matsuda, T.; Meshcheryakov, G.; Meyer, W.; Michigami, T.; Mikhailov, Yu.V.; Moinester, M.A.; Morreale, A.; Mutter, A.; Nagaytsev, A.; Nagel, T.; Negrini, T.; Nerling, F.; Neubert, S.; Neyret, D.; Nikolaenko, V.I.; Nowak, W.D.; Nunes, A.S.; Olshevsky, A.G.; Ostrick, M.; Padee, A.; Panknin, R.; Panzieri, D.; Parsamyan, B.; Paul, S.; Perevalova, E.; Pesaro, G.; Peshekhonov, D.V.; Piragino, G.; Platchkov, S.; Pochodzalla, J.; Polak, J.; Polyakov, V.A.; Pretz, J.; Quaresma, M.; Quintans, C.; Rajotte, J.F.; Ramos, S.; Rapatsky, V.; Reicherz, G.; Richter, A.; Rocco, E.; Rondio, E.; Rossiyskaya, N.S.; Ryabchikov, D.I.; Samoylenko, V.D.; Sandacz, A.; Sapozhnikov, M.G.; Sarkar, S.; Savin, I.A.; Sbrizzai, G.; Schiavon, P.; Schill, C.; Schluter, T.; Schmidt, K.; Schmitt, L.; Schonning, K.; Schopferer, S.; Schott, M.; Schroder, W.; Shevchenko, O.Yu.; Silva, L.; Sinha, L.; Sissakian, A.N.; Slunecka, M.; Smirnov, G.I.; Sosio, S.; Sozzi, F.; Srnka, A.; Steiger, L.; Stolarski, M.; Sulc, M.; Sulej, R.; Suzuki, H.; Sznajder, P.; Takekawa, S.; Ter Wolbeek, J.; Tessaro, S.; Tessarotto, F.; Tkatchev, L.G.; Uhl, S.; Uman, I.; Vandenbroucke, M.; Virius, M.; Vlassov, N.V.; Wang, L.; Wilfert, M.; Windmolders, R.; Wislicki, W.; Wollny, H.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zhuravlev, N.; Zvyagin, A.

    2012-01-01

    The transverse target spin azimuthal asymmetry A_UT in hard exclusive production of rho^0 mesons was measured at COMPASS by scattering 160 GeV/c muons off transversely polarised protons and deuterons. The measured asymmetry is sensitive to the nucleon helicity-flip generalised parton distributions E^q, which are related to the orbital angular momentum of quarks in the nucleon. The Q^2, x_B and p_t^2 dependence of A_UT is presented in a wide kinematic range. Results for deuterons are obtained for the first time. The measured asymmetry is small in the whole kinematic range for both protons and deuterons, which is consistent with the theoretical interpretation that contributions from GPDs E^u and E^d approximately cancel.

  19. Large-Angle CMB Suppression and Polarisation Predictions

    CERN Document Server

    Copi, C.J.; Schwarz, D.J.; Starkman, G.D.

    2013-01-01

    The anomalous lack of large angle temperature correlations has been a surprising feature of the CMB since first observed by COBE-DMR and subsequently confirmed and strengthened by WMAP. This anomaly may point to the need for modifications of the standard model of cosmology or may show that our Universe is a rare statistical fluctuation within that model. Further observations of the temperature auto-correlation function will not elucidate the issue; sufficiently high precision statistical observations already exist. Instead, alternative probes are required. In this work we explore the expectations for forthcoming polarisation observations. We define a prescription to test the hypothesis that the large-angle CMB temperature perturbations in our Universe represent a rare statistical fluctuation within the standard cosmological model. These tests are based on the temperature-Q Stokes parameter correlation. Unfortunately these tests cannot be expected to be definitive. However, we do show that if this TQ-correlati...

  20. Investigating pitting in X65 carbon steel using potentiostatic polarisation

    Science.gov (United States)

    Mohammed, Sikiru; Hua, Yong; Barker, R.; Neville, A.

    2017-11-01

    Although pitting corrosion in passive materials is generally well understood, the growth of surface pits in actively-corroding materials has received much less attention to date and remains poorly understood. One of the key challenges which exists is repeatedly and reliably generating surface pits in a practical time-frame in the absence of deformation and/or residual stress so that studies on pit propagation and healing can be performed. Another pertinent issue is how to evaluate pitting while addressing general corrosion in low carbon steel. In this work, potentiostatic polarisation was employed to induce corrosion pits (free from deformation or residual stress) on actively corroding X65 carbon steel. The influence of applied potential (50 mV, 100 mV and 150 mV vs open circuit potential) was investigated over 24 h in a CO2-saturated, 3.5 wt.% NaCl solution at 30 °C and pH 3.8. Scanning electron microscopy (SEM) was utilised to examine pits, while surface profilometry was conducted to measure pit depth as a function of applied potential over the range considered. Analyses of light pitting (up to 120 μm) revealed that pit depth increased linearly with increase in applied potential. This paper relates total pit volume (measured using white light interferometry) to dissipated charge or total mass loss (using the current response for potentiostatic polarisation in conjunction with Faraday's law). By controlling the potential of the surface (anodic) the extent of pitting and general corrosion could be controlled. This allowed pits to be evaluated for their ability to continue to propagate after the potentiostatic technique was employed. Linear growth from a depth of 70 μm at pH 3.8, 80 °C was demonstrated. The technique offers promise for the study of inhibition of pitting.

  1. Improving Image Matching by Reducing Surface Reflections Using Polarising Filter Techniques

    Science.gov (United States)

    Conen, N.; Hastedt, H.; Kahmen, O.; Luhmann, T.

    2018-05-01

    In dense stereo matching applications surface reflections may lead to incorrect measurements and blunders in the resulting point cloud. To overcome the problem of disturbing reflexions polarising filters can be mounted on the camera lens and light source. Reflections in the images can be suppressed by crossing the polarising direction of the filters leading to homogeneous illuminated images and better matching results. However, the filter may influence the camera's orientation parameters as well as the measuring accuracy. To quantify these effects, a calibration and an accuracy analysis is conducted within a spatial test arrangement according to the German guideline VDI/VDE 2634.1 (2002) using a DSLR with and without polarising filter. In a second test, the interior orientation is analysed in more detail. The results do not show significant changes of the measuring accuracy in object space and only very small changes of the interior orientation (Δc ≤ 4 μm) with the polarising filter in use. Since in medical applications many tiny reflections are present and impede robust surface measurements, a prototypic trinocular endoscope is equipped with polarising technique. The interior and relative orientation is determined and analysed. The advantage of the polarising technique for medical image matching is shown in an experiment with a moistened pig kidney. The accuracy and completeness of the resulting point cloud can be improved clearly when using polarising filters. Furthermore, an accuracy analysis using a laser triangulation system is performed and the special reflection properties of metallic surfaces are presented.

  2. Efficient simulations of the aqueous bio-interface of graphitic nanostructures with a polarisable model

    Science.gov (United States)

    Hughes, Zak E.; Tomásio, Susana M.; Walsh, Tiffany R.

    2014-04-01

    To fully harness the enormous potential offered by interfaces between graphitic nanostructures and biomolecules, detailed connections between adsorbed conformations and adsorption behaviour are needed. To elucidate these links, a key approach, in partnership with experimental techniques, is molecular simulation. For this, a force-field (FF) that can appropriately capture the relevant physics and chemistry of these complex bio-interfaces, while allowing extensive conformational sampling, and also supporting inter-operability with known biological FFs, is a pivotal requirement. Here, we present and apply such a force-field, GRAPPA, designed to work with the CHARMM FF. GRAPPA is an efficiently implemented polarisable force-field, informed by extensive plane-wave DFT calculations using the revPBE-vdW-DF functional. GRAPPA adequately recovers the spatial and orientational structuring of the aqueous interface of graphene and carbon nanotubes, compared with more sophisticated approaches. We apply GRAPPA to determine the free energy of adsorption for a range of amino acids, identifying Trp, Tyr and Arg to have the strongest binding affinity and Asp to be a weak binder. The GRAPPA FF can be readily incorporated into mainstream simulation packages, and will enable large-scale polarisable biointerfacial simulations at graphitic interfaces, that will aid the development of biomolecule-mediated, solution-based graphene processing and self-assembly strategies.To fully harness the enormous potential offered by interfaces between graphitic nanostructures and biomolecules, detailed connections between adsorbed conformations and adsorption behaviour are needed. To elucidate these links, a key approach, in partnership with experimental techniques, is molecular simulation. For this, a force-field (FF) that can appropriately capture the relevant physics and chemistry of these complex bio-interfaces, while allowing extensive conformational sampling, and also supporting inter

  3. An introduction to cross-sections and asymmetries measurable using polarised beams in high-energy e+e- colliders

    International Nuclear Information System (INIS)

    Clarke, P.

    1990-08-01

    The implementation of polarised beams at SLC, and hopefully LEP, is an important development. This will allow access to a range of precision measurements which exploit the parity violating nature of the Z boson. This report gives an introduction to the basic quantities which may be measured with polarised beams. These are the left-right asymmetry (A LR ), forward-backward asymmetries with and without polarisation (A R FB , A L FB , A FB ) and the ''improved'' polarised forward-backward asymmetry (A pol FB ). The final state polarisation measurement is also discussed. (author)

  4. Spontaneous polyploidization in cucumber.

    Science.gov (United States)

    Ramírez-Madera, Axel O; Miller, Nathan D; Spalding, Edgar P; Weng, Yiqun; Havey, Michael J

    2017-07-01

    This is the first quantitative estimation of spontaneous polyploidy in cucumber and we detected 2.2% polyploids in a greenhouse study. We provide evidence that polyploidization is consistent with endoreduplication and is an on-going process during plant growth. Cucumber occasionally produces polyploid plants, which are problematic for growers because these plants produce misshaped fruits with non-viable seeds. In this study, we undertook the first quantitative study to estimate the relative frequency of spontaneous polyploids in cucumber. Seeds of recombinant inbred lines were produced in different environments, plants were grown in the field and greenhouse, and flow cytometry was used to establish ploidies. From 1422 greenhouse-grown plants, the overall relative frequency of spontaneous polyploidy was 2.2%. Plants possessed nuclei of different ploidies in the same leaves (mosaic) and on different parts of the same plant (chimeric). Our results provide evidence of endoreduplication and polysomaty in cucumber, and that it is an on-going and dynamic process. There was a significant effect (p = 0.018) of seed production environment on the occurrence of polyploid plants. Seed and seedling traits were not accurate predictors of eventual polyploids, and we recommend that cucumber producers rogue plants based on stature and leaf serration to remove potential polyploids.

  5. Dynamic proton polarisation on polymers in solution: creating contrast in neutron scattering

    International Nuclear Information System (INIS)

    Grinten, M.G.D. van der

    1995-01-01

    Dynamic nuclear polarisation (DNP) as an alternative or additional method to create contrast in neutron small angle scattering has been investigated with emphasis on the study of polymers in solution. The need for high polarisations imposes specific requirements on the sample and its environment. Vitreous beads have been used as samples. Nuclear relaxation times show that they contain dissolved air. Parasitic scattering from the solvent is observed, probably arising from nanometer air bubbles. DNP is shown to be useful, in particular for samples that consist of mixtures of hydrogen-free and hydrogen-rich molecules, where the different molecules can be highlighted by changing the polarisation. ((orig.))

  6. Polarisation and compression of 3He for Magnetic Resonance Imaging purposes

    International Nuclear Information System (INIS)

    Geurts, D. G.; Brand, J. F. J. van den; Bulten, H. J.; Poolman, H. R.; Ferro-Luzzi, M.; Nicolay, K.

    1998-01-01

    Magnetic Resonance Imaging is often used in medical science as a diagnostic tool for the human body. Conventional MRI uses the NMR signal from the protons of water molecules in tissue to image the interior of the patient's body. However, for certain areas such as the lungs and airways, the usage of a highly polarised gas yields better results. We are currently constructing an apparatus that uses polarised 3 He gas to produce detailed images of those signal-deficient moyeties. We also plan to study possible uptake of polarised 3 He gas by the circulatory system to image other organs

  7. Direct Measurement of the Gluon Polarisation in the Nucleon via Charmed Meson Production

    CERN Document Server

    Alekseev, M; Alexandrov, Yu; Alexeev, G D; Amoroso, A; Arbuzov, A; Badelek, Barbara Maria; Balestra, F; Ball, J; Barth, J; Baum, Guenter; Bedfer, Y; Bernet, Colin; Bertini, R; Bettinelli, M; Birsa, R; Bisplinghoff, J; Bordalo, P; Bradamante, Franco; Brona, G; Burtin, E; Bussa, M P; Chapiro, A; Chiosso, M; Cicuttin, A; Colantoni, M; Crespo, M L; Dalla Torre, S; Dafni, T; Das, S; Dasgupta, S S; De Masi, R; Dedek, N; Dhara, L; Diaz, V; Dinkelbach, A M; Donskov, S V; Dorofeev, V A; Doshita, N; Duic, V; Dunnweber, W; Eversheim, P D; Eyrich, W; Faessler, M; Falaleev, V; Ferrero, L; Finger, M; Finger, M., Jr; Fischer, H; Franco, C; Franz, J; Friedrich, J M; Garfagnini, R; Gautheron, Fabrice; Gavrichtchouk, O P; Gazda, R; Geyer, R; Giorgi, M; Gobbo, Benigno; Gorin, A M; Grabmuller, S; Grajek, O A; Grasso, A; Grube, B; Gushterski, R; Guskov, A; Haas, F; Hannappel, J; von Harrach, D; Hasegawa, T; Heckmann, J; Hedicke, S; Heinsius, Fritz-Herbert; Hermann, R; Hess, C; Hinterberger, F; von Hodenberg, M; Horikawa, S; d'Hose, N; Ilgner, C; Ioukaev, A I; Ishimoto, S; Ivanov, O; Ivanshin, Yu; Jahn, R; Janata, A; Jasinski, P; Joosten, R; Jouravlev, N I; Kabuss, E; Kang, D; Ketzer, Bernhard; Khaustov, G V; Khokhlov, Yu A; Klein, F; Klimaszewski, K; Koblitz, S; Kolosov, V N; Komissarov, E V; Kondo, K; Konigsmann, Kay; Konstantinov, V F; Korentchenko, A S; Koutchinski, N A; Kral, A; Kravchuk, N P; Kroumchtein, Z V; Kuhn, R; Kunne, Fabienne; Kurek, Krzysztof; Ladygin, M E; Le Goff, Jean-Marc; Lednev, A A; Lehmann, A; Levorato, S; Lichtenstadt, J; Liska, T; Ludwig, I; Maggiora, A; Maggiora, M; Magnon, A; Mallot, G K; Mann, A; Marchand, C; Marroncle, J; Martin, A; Marzec, J; Massmann, F; Matsuda, T; Meyer, W.Thomas; Mikhailov, Yu V; Moinester, M A; Nagaytsev, A; Nagel, T; Nahle, O; Nassalski, J; Neliba, S; Nerling, F; Neubert, S; Neyret, D P; Nikolaenko, V I; Nikolaev, K; Olshevsky, A G; Ostrick, M; Padee, A; Pagano, P; Panebianco, S; Panknin, R; Panzieri, D; Paul, S; Pawlukiewicz-Kaminska, B; Peshekhonov, D V; Peshekhonov, V D; Piragino, G; Platchkov, Stephane; Pochodzalla, J; Polak, J; Polyakov, V A; Pretz, J; Procureur, S; Quintans, C; Rajotte, J F; Ramos, S.; Rapatsky, V; Reicherz, G; Reggiani, D; Richter, A; Robinet, F; Rondio, Ewa; Rozhdestvensky, A M; Ryabchikov, D I; Samoylenko, V D; Sandacz, A; Sapozhnikov, M G; Sarkar, S; Savin, Igor A; Schiavon, P; Schill, Christian; Schonmeier, P; Schroder, W; Shevchenko, O Yu; Silva, L; Sinha, L; Sissakian, A N; Slunecka, M; Smirnov, G I; Sosio, S; Sozzi, F; Srnka, A; Stinzing, F; Sugonyaev, V P; Sulc, M; Sulej, R; Tchalishev, V V; Tessaro, S; Tessarotto, F; Teufel, A; Tkatchev, L G; Venugopal, G; Virius, M; Vlassov, N V; Vossen, A; Webb, Robert C; Weitzel, Q; Windmolders, R; Wirth, S; Wislicki, W; Wollny, H; Zaremba, K; Zavertyaev, M; Zemlyanichkina, E; Ziegler, R; Zvyagin, A

    2008-01-01

    We present the first measurement of the gluon polarisation in the nucleon based on the photon-gluon fusion process tagged by charmed meson production and decay to charged K and pi. The data were collected in polarised muon scattering off a polarised deuteron target by the COMPASS collaboration at CERN during 2002-2004. The result of this LO analysis is _x = -0.47 +- 0.44 (stat) +- 0.15 (syst) at ~= 0.11 and a scale mu^2 ~ 13 (GeV/c)^2.

  8. Linear to Circular Polarisation Conversion using Birefringent Properties of Aligned Crystals for Multi-GeV Photons

    CERN Document Server

    Apyan, A.; Badelek, B.; Ballestrero, S.; Biino, C.; Birol, I.; Cenci, P.; Connell, S.H.; Eichblatt, S.; Fonseca, T.; Freund, A.; Gorini, B.; Groess, R.; Ispirian, K.; Ketel, T.J.; Kononets, Yu.V.; Lopez, A.; Mangiarotti, A.; van Rens, B.; Sellschop, J.P.F.; Shieh, M.; Sona, P.; Strakhovenko, V.; Uggerhoj, E.; Uggerhj, Ulrik Ingerslev; Unel, G.; Velasco, M.; Vilakazi, Z.Z.; Wessely, O.; Kononets, Yu.V.

    2003-01-01

    We present the first experimental results on the use of a thick aligned Si crystal acting as a quarter wave plate to induce a degree of circular polarisation in a high energy linearly polarised photon beam. The linearly polarised photon beam is produced from coherent bremsstrahlung radiation by 178 GeV unpolarised electrons incident on an aligned Si crystal, acting as a radiator. The linear polarisation of the photon beam is characterised by measuring the asymmetry in electron-positron pair production in a Ge crystal, for different crystal orientations. The Ge crystal therefore acts as an analyser. The birefringence phenomenon, which converts the linear polarisation to circular polarisation, is observed by letting the linearly polarised photons beam pass through a thick Si quarter wave plate crystal, and then measuring the asymmetry in electron-positron pair production again for a selection of relative angles between the crystallographic planes of the radiator, analyser and quarter wave plate. The systematics...

  9. Gauge theories as theories of spontaneous breakdown

    International Nuclear Information System (INIS)

    Ivanov, E.A.; Ogievetsky, V.I.

    1976-01-01

    Any gauge theory is proved to arise from spontaneous breakdown of symmetry under certain infinite parameter group, the corresponding gauge field being the Goldstone field by which this breakdown is accompanied

  10. Spontaneous soldering

    International Nuclear Information System (INIS)

    Percacci, R.

    1984-01-01

    It is proposed that the soldering form of general relativity be treated as a dynamical variable. This gives rise to the possibility of treating the linear connection on (n-dimensional) spacetime and an internal O(k)-Yang-Mills field as different components of the same O(N) gauge field (N= n+k). The distinction between gravitational and Yang-Mills interactions is due to a kind of Higgs mechanism driven by the vacuum expectation value of the soldering form. (orig.)

  11. Measurement of the polarisation of a muon beam of 190 GeV by scattering on a target of polarised electrons

    International Nuclear Information System (INIS)

    Burtin, Etienne

    1996-01-01

    This research thesis reports the development of a muon-based polarimeter which implements elastic scattering of muons on a target of polarised electrons. In its first part, it describes the deeply inelastic scattering process, and presents the theoretical framework for the interpretation of experimental results. The author describes the experimental installation, and the measurement of the beam polarisation by elastic scattering on a target of polarised electrons. He reports the analysis of data obtained with a 190 GeV beam, the discussion and assessment of error sources, the comparison of these results with other measurements using the muon in-flight disintegration, and with the prediction obtained by the beam line simulation. He finally reports the results of the SMC experiment obtained for the proton and the deuteron, and demonstrates the verification of the Bjorken sum rule

  12. Inclusive and semi-inclusive analysis from polarised deep-inelastic muon scattering

    International Nuclear Information System (INIS)

    Kageya, T.

    1999-01-01

    We present new results for the spin-dependent structure function on the proton and for the polarised quark distributions in the nucleon from semi-inclusive spin asymmetries. With the inclusive asymmetry from deep inelastic scattering of polarised muons on polarised protons, it is found that the Ellis-Jaffe sum rule is violated. Using our results for Γ d 1 , the Bjorken sum rule is confirmed with an accuracy of about 15%. From semi-inclusive spin asymmetries and SMC inclusive spin asymmetries, we determine the polarised quark distributions of valence u and d quarks to be positive and negative, respectively, while the non-strange sea distribution to be consistent with zero

  13. Heavy-quark QCD vacuum polarisation function. Analytical results at four loops

    International Nuclear Information System (INIS)

    Kniehl, B.A.; Kotikov, A.V.

    2006-07-01

    The first two moments of the heavy-quark vacuum polarisation function at four loops in quantum chromo-dynamics are found in fully analytical form by evaluating the missing massive four-loop tadpole master integrals. (orig.)

  14. Gluon Polarisation in the Nucleon and Longitudinal Double Spin Asymmetries from Open Charm Muoproduction

    CERN Document Server

    Alekseev, M; Alexandrov, Yu; Alexeev, G D; Amoroso, A; Austregisilio, A; Badelek, B; Balestra, F; Ball, J; Barth, J; Baum, G; Bedfer, Y; Bernhard, J; Bertini, R; Bettinelli, M; Birsa, R; Bisplinghoff, J; Bordalo, P; Bradamante, F; Bravar, A; Bressan, A; Brona, G; Burtin, E; Bussa, M P; Chapiro, A; Chiosso, M; Chung, S U; Cicuttin, A; Colantoni, M; Crespo, M L; Dalla Torre, S; Dafni, T; Das, S; Dasgupta, S S; Denisov, O.Yu; Dhara, L; Diaz, V; Dinkelbach, A M; Donskov, S V; Doshita, N; Duic, V; Dunnweber, W; Efremov, A; El Alaoui, A; Eversheim, P D; Eyrich, W; Faessler, M; Ferrero, A; Finger, M; Finger, M., jr; Fischer, H; Franco, C; Friedrich, J M; Garfagnini, R; Gautheron, F; Gavrichtchouk, O P; Gazda, R; Gerassimov, S; Geyer, R; Giorgi, M; Gobbo, B; Goertz, S; Grabmuller, S; Grajek, O A; Grasso, A; Grube, B; Gushterski, R; Guskov, A; Haas, F; Hagemann, R; von Harrach, D; Hasegawa, T; Heckmann, J; Heinsius, F H; Hermann, R; Herrmann, F; Hess, C; Hinterberger, F; von Hodenberg, M; Horikawa, N; Hoppner, Ch; d'Hose, N; Ilgner, C; Ishimoto, S; Ivanov, O; Ivanshin, Yu; Iwata, T; Jahn, R; Jasinski, P; Jegou, G; Joosten, R; Kabuss, E; Kafer, W; Kang, D; Ketzer, B; Khaustov, G V; Khokhlov, Yu.A; Kiefer, J; Kisselev, Yu; Klein, F; Klimaszewski, K; Koblitz, S; Koivuniemi, J H; Kolosov, V N; Komissarov, E V; Kondo, K; Konigsmann, Kay; Konorov, I; Konstantinov, V F; Korzenev, A; Kotzinian, A M; Kouznetsov, O; Kowalik, K; Kramer, M; Kral, A; Kroumchtein, Z V; Kuhn, R; Kunne, F; Kurek, K; Le Goff, J M; Lednev, A A; Lehmann, A; Levorato, S; Lichtenstadt, J; Liska, T; Maggiora, A; Maggiora, M; Magnon, A; Mallot, G K; Mann, A; Marchand, C; Marroncle, J; Martin, A; Marzec, J; Massmann, F; Matsuda, T; Maximov, A N; Meyer, W; Michigami, T; Mikhailov, Yu.V; Moinester, M A; Mutter, A; Nagaytsev, A; Nagel, T; Nassalski, J; Negrini, S; Nerling, F; Neubert, S; Neyret, D; Nikolaenko, V I; Olshevsky, A G; Ostrick, M; Padee, A; Panknin, R; Panebianco, S; Panzieri, D; Parsamyan, B; Paul, S; Pawlukiewicz-Kaminska, B; Perevalova, E; Pesaro, G; Peshekhonov, D V; Piragino, G; Platchkov, S; Pochodzalla, J; Polak, J; Polyakov, V A; Pontecorvo, G; Pretz, J; Quintans, C; Rajotte, J.-F; Ramos, S; Rapatsky, V; Reicherz, G; Reggiani, D; Richter, A; Robinet, F; Rocco, E; Rondio, E; Ryabchikov, D I; Samoylenko, V D; Sandacz, A; Santos, H; Sapozhnikov, M G; Sarkar, S; Savin, Igor A; Sbrizza, G; Schiavon, P; Schill, C; Schmitt, L; Schroder, W; Shevchenko, O.Yu; Siebert, H.-W; Silva, L; Sinha, L; Sissakian, A N; Slunecka, M; Smirnov, G I; Sosio, S; Sozzi, F; Srnka, A; Stolarski, M; Sulc, M; Sulej, R; Takekawa, S; Tessaro, S; Tessarotto, F; Teufel, A; Tkatchev, L G; Venugopal, G; Virius, M; Vlassov, N V; Vossen, A; Weitzel, Q; Wenzl, K; Windmolders, R; Wislicki, W; Wollny, H; Zaremba, K; Zavertyaev, M; Zemlyanichkina, E; Ziembicki, M; Zhao, J; Zhuravlev, N; Zvyagin, A

    2009-01-01

    The gluon polarisation in the nucleon has been determined by detecting charm production via D0 meson decay to charged K and pi in polarised muon scattering off a longitudinally polarised deuteron target. The data were taken by the COMPASS Collaboration at CERN between 2002 and 2006 and corresponds to an integrated luminosity of 2.8 fb^-1. The dominant underlying process of charm production is the photon-gluon fusion to a cc-bar pair. A leading order QCD approach gives an average gluon polarisation of (Delta g/g)_x= -0.49 +- 0.27(stat) +- 0.11(syst) at a scale mu^2 ~ 13 (GeV/c)^2 and at an average gluon momentum fraction (x) ~ 0.11. The longitudinal cross-section asymmetry for D0 production is presented in bins of the transverse momentum and the energy of the D0 meson.

  15. First Measurement of Charged Current Cross Sections at HERA with Longitudinally Polarised Positrons

    CERN Document Server

    Aktas, A.; Anthonis, T.; Antunovic, B.; Aplin, S.; Asmone, A.; Astvatsatourov, A.; Babaev, A.; Backovic, S.; Bahr, J.; Baghdasaryan, A.; Baranov, P.; Barrelet, E.; Bartel, W.; Baudrand, S.; Baumgartner, S.; Becker, J.; Beckingham, M.; Behnke, O.; Behrendt, O.; Belousov, A.; Berger, Ch.; Berger, N.; Bizot, J.C.; Boenig, M.-O.; Boudry, V.; Bracinik, J.; Brandt, G.; Brisson, V.; Bruncko, D.; Busser, F.W.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A.J.; Cassol-Brunner, F.; Cerny, K.; Cerny, V.; Chekelian, V.; Contreras, J.G.; Coughlan, J.A.; Cox, B.E.; Cozzika, G.; Cvach, J.; Dainton, J.B.; Dau, W.D.; Daum, K.; de Boer, Y.; Delcourt, B.; Del Degan, M.; De Roeck, A.; Desch, K.; De Wolf, E.A.; Diaconu, C.; Dodonov, V.; Dubak, A.; Eckerlin, Guenter; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Elsen, E.; Erdmann, W.; Essenov, S.; Falkewicz, A.; Faulkner, P.J.W.; Favart, L.; Fedotov, A.; Feltesse, J.; Ferencei, J.; Finke, L.; Fleischer, M.; Fleischmann, P.; Flucke, G.; Fomenko, A.; Foresti, I.; Franke, G.; Frisson, T.; Gabathuler, E.; Garutti, E.; Gayler, J.; Gerlich, C.; Ghazaryan, Samvel; Ginzburgskaya, S.; Glazov, A.; Glushkov, I.; Goerlich, L.; Goettlich, M.; Gogitidze, N.; Gorbounov, S.; Goyon, C.; Grab, C.; Greenshaw, T.; Gregori, M.; Grell, B.R.; Grindhammer, Guenter; Gwilliam, C.; Haidt, D.; Hajduk, L.; Hansson, M.; Heinzelmann, G.; Henderson, R.C.W.; Henschel, H.; Herrera, G.; Hildebrandt, M.; Hiller, K.H.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Hreus, T.; Hussain, S.; Ibbotson, M.; Ismail, M.; Jacquet, M.; Janauschek, L.; Janssen, X.; Jemanov, V.; Jonsson, L.; Johnson, D.P.; Jung, Andreas Werner; Jung, H.; Kapichine, M.; Katzy, J.; Kenyon, I.R.; Kiesling, Christian M.; Klein, M.; Kleinwort, C.; Klimkovich, T.; Kluge, T.; Knies, G.; Knutsson, A.; Korbel, V.; Kostka, P.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Kruger, K.; Kuckens, J.; Landon, M.P.J.; Lange, W.; Lastovicka, T.; Lastovicka-Medin, G.; Laycock, P.; Lebedev, A.; Leibenguth, G.; Lendermann, V.; Levonian, S.; Lindfeld, L.; Lipka, K.; Liptaj, A.; List, B.; List, J.; Lobodzinska, E.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lucaci-Timoce, A.-I.; Lueders, H.; Luke, D.; Lux, T.; Lytkin, L.; Makankine, A.; Malden, N.; Malinovski, E.; Mangano, S.; Marage, P.; Marshall, R.; Martisikova, M.; Martyn, H.-U.; Maxfield, S.J.; Meer, D.; Mehta, A.; Meier, K.; Meyer, A.B.; Meyer, H.; Meyer, J.; Michels, V.; Mikocki, S.; Milcewicz-Mika, I.; Milstead, D.; Mladenov, D.; Mohamed, A.; Moreau, F.; Morozov, A.; Morris, J.V.; Mozer, Matthias Ulrich; Muller, K.; Murin, P.; Nankov, K.; Naroska, B.; Naumann, Th.; Newman, Paul R.; Niebuhr, C.; Nikiforov, A.; Nowak, G.; Nozicka, M.; Oganezov, R.; Olivier, B.; Olsson, J.E.; Osman, S.; Ozerov, D.; Palichik, V.; Panagoulias, I.; Papadopoulou, T.; Pascaud, C.; Patel, G.D.; Peng, H.; Perez, E.; Perez-Astudillo, D.; Perieanu, A.; Petrukhin, A.; Pitzl, D.; Placakyte, R.; Portheault, B.; Povh, B.; Prideaux, P.; Rahmat, A.J.; Raicevic, N.; Reisert, B.; Reimer, P.; Rimmer, A.; Risler, C.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rurikova, Z.; Rusakov, S.; Salvaire, F.; Sankey, D.P.C.; Sauvan, E.; Schatzel, S.; Schmidt, S.; Schmitt, S.; Schmitz, C.; Schoeffel, L.; Schoning, A.; Schultz-Coulon, H.-C.; Sedlak, K.; Sefkow, F.; Shaw-West, R.N.; Sheviakov, I.; Shtarkov, L.N.; Sloan, T.; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, Arnd E.; Steder, M.; Stella, B.; Stiewe, J.; Strauch, I.; Straumann, U.; Sunar, D.; Tchoulakov, V.; Thompson, Graham; Thompson, P.D.; Tomasz, F.; Traynor, D.; Truoel, Peter; Tsakov, I.; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Urban, K.; Usik, A.; Utkin, D.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Vargas Trevino, A.; Vazdik, Y.; Veelken, C.; Vinokurova, S.; Volchinski, V.; Wacker, K.; Wagner, J.; Weber, G.; Weber, R.; Wegener, D.; Werner, C.; Wessels, M.; Wessling, B.; Wigmore, C.; Wissing, Ch.; Wolf, R.; Wunsch, E.; Xella, S.; Yan, W.; Yeganov, V.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhelezov, A.; Zhokin, A.; Zhu, Y.C.; Zimmermann, J.; Zimmermann, T.; Zohrabyan, H.; Zomer, F.

    2006-01-01

    Data taken with positrons of different longitudinal polarisation states in collision with unpolarised protons at HERA are used to measure the total cross sections of the charged current process, e^+ p \\to \\bar{\

  16. On cloud ice induced absorption and polarisation effects in microwave limb sounding

    Directory of Open Access Journals (Sweden)

    P. Eriksson

    2011-06-01

    Full Text Available Microwave limb sounding in the presence of ice clouds was studied by detailed simulations, where clouds and other atmospheric variables varied in three dimensions and the full polarisation state was considered. Scattering particles were assumed to be horizontally aligned oblate spheroids with a size distribution parameterized in terms of temperature and ice water content. A general finding was that particle absorption is significant for limb sounding, which is in contrast to the down-looking case, where it is usually insignificant. Another general finding was that single scattering can be assumed for cloud optical paths below about 0.1, which is thus an important threshold with respect to the complexity and accuracy of retrieval algorithms. The representation of particle sizes during the retrieval is also discussed. Concerning polarisation, specific findings were as follows: Firstly, no significant degree of circular polarisation was found for the considered particle type. Secondly, for the ±45° polarisation components, differences of up to 4 K in brightness temperature were found, but differences were much smaller when single scattering conditions applied. Thirdly, the vertically polarised component has the smallest cloud extinction. An important goal of the study was to derive recommendations for future limb sounding instruments, particularly concerning their polarisation setup. If ice water content is among the retrieval targets (and not just trace gas mixing ratios, then the simulations show that it should be best to observe any of the ±45° and circularly polarised components. These pairs of orthogonal components also make it easier to combine information measured from different positions and with different polarisations.

  17. The interaction of circularly polarised electromagnetic waves with a plasma; Interaction d'ondes electromagnetiques a polarisation circulaire avec un plasma

    Energy Technology Data Exchange (ETDEWEB)

    Consoli, T; Legardeur, R; Slama, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    The interaction of left and right handed circularly polarised waves with a plasma are studied. The individual trajectories of charges of both signs are traced with a analogical simulator. Applications to plasma heating and diagnostic are deduced. (author) [French] On etudie l'interaction des ondes a polarisation circulaire droite ou gauche avec un plasma. Les trajectoires individuelles des charges sont tracees a l'aide d'un dispositif analogique. On en deduit les applications au chauffage d'un plasma et a la mesure de ses parametres caracteristiques. (auteur)

  18. Polarised quark distributions in the nucleon from semi-inclusive spin asymmetries

    CERN Document Server

    Adeva, B; Arik, E; Arvidson, A; Badelek, B; Bardin, G; Baum, G; Berglund, P; Betev, L; Birsa, R; De Botton, N R; Bradamante, Franco; Bravar, A; Bressan, A; Bültmann, S; Burtin, E; Crabb, D; Cranshaw, J; Çuhadar-Dönszelmann, T; Dalla Torre, S; Van Dantzig, R; Derro, B R; Deshpande, A A; Dhawan, S K; Dulya, C M; Eichblatt, S; Fasching, D; Feinstein, F; Fernández, C; Forthmann, S; Frois, Bernard; Gallas, A; Garzón, J A; Gilly, H; Giorgi, M A; von Goeler, E; Görtz, S; Gracia, G; De Groot, N; Grosse-Perdekamp, M; Haft, K; Von Harrach, D; Hasegawa, T; Hautle, P; Hayashi, N; Heusch, C A; Horikawa, N; Hughes, V W; Igo, G; Ishimoto, S; Iwata, S; Kabuss, E M; Kageya, T; Karev, A G; Kessler, H J; Ketel, T; Kiryluk, J; Kiselev, Yu F; Krämer, Dietrich; Krivokhizhin, V G; Kröger, W; Kukhtin, V V; Kurek, K; Kyynäräinen, J; Lamanna, M; Landgraf, U; Le Goff, J M; Lehár, F; de Lesquen, A; Lichtenstadt, J; Litmaath, M; Magnon, A; Mallot, G K; Marie, F; Martin, A; Martino, J; Matsuda, T; Mayes, B W; McCarthy, J S; Medved, K S; Meyer, W T; Van Middelkoop, G; Miller, D; Miyachi, Y; Mori, K; Moromisato, J H; Nassalski, J P; Naumann, Lutz; Niinikoski, T O; Oberski, J; Ogawa, A; Ozben, C; Pereira, H; Perrot-Kunne, F; Peshekhonov, V D; Pinsky, L; Platchkov, S K; Pló, M; Pose, D; Postma, H; Pretz, J; Puntaferro, R; Rädel, G; Rijllart, A; Reicherz, G; Roberts, J; Rodríguez, M; Rondio, Ewa; Roscherr, B; Sabo, I; Saborido, J; Sandacz, A; Savin, I A; Schiavon, R P; Schiller, A; Sichtermann, E P; Simeoni, F; Smirnov, G I; Staude, A; Steinmetz, A; Stiegler, U; Stuhrmann, H B; Szleper, M; Tessarotto, F; Thers, D; Tlaczala, W; Tripet, A; Ünel, G; Velasco, M; Vogt, J; Voss, Rüdiger; Whitten, C; Windmolders, R; Willumeit, R; Wislicki, W; Witzmann, A; Ylöstalo, J; Zanetti, A M; Zaremba, K; Zhao, J

    1998-01-01

    We present a measurement of semi-inclusive spin asymmetries for positively and negatively charged hadrons from deep inelastic scattering of polarised muons on polarised protons and deuterons in the range $0.003$1~GeV$^2$. Compared to our previous publication on this subject, with the new data the statistical errors have been reduced by nearly a factor of two. From these asymmetries and our inclusive spin asymmetries we determine the polarised quark distributions of valence quarks and non-strange sea quarks at $Q^2$=10~GeV$^2$. The polarised $u$ valence quark distribution, $\\Delta u_v(x)$, is positive and the polarisation increases with $x$. The polarised $d$ valence quark distribution, $\\Delta d_v(x)$, is negative and the non-strange sea distribution, $\\Delta \\bar q(x)$, is consistent with zero over the measured range of $x$. We find for the first moments $\\int_0^1 \\Delta u_v(x) {\\rm d}x = 0.77 \\pm 0.10 \\pm 0.08$, $\\int_0^1 \\Delta d_v(x) {\\rm d}x = -0.52 \\pm 0.14 \\pm 0.09$ and $\\int_0^1 \\Delta \\bar q(x) {\\rm ...

  19. Modelling magnetic polarisation J 50 by different methods

    International Nuclear Information System (INIS)

    Yonamine, Taeko; Campos, Marcos F. de; Castro, Nicolau A.; Landgraf, Fernando J.G.

    2006-01-01

    Two different methods for modelling the angular behaviour of magnetic polarisation at 5000 A/m (J 50 ) of electrical steels were evaluated and compared. Both methods are based upon crystallographic texture data. The texture of non-oriented electrical steels with silicon content ranging from 0.11 to 3%Si was determined by X-ray diffraction. In the first method, J 50 was correlated to the calculated value of the average anisotropy energy in each direction, using texture data. In the second method, the first three coefficients of the spherical harmonic series of the ODF and two experimental points were used to estimate the angular variation of J 50 . The first method allows the estimation of J 50 for samples with different textures and Si contents using only the texture data, with no need of magnetic measurement, and this is advantageous, because texture data can be acquired with less than 2 g of material. The second method may give better adjust in some situations but besides the texture data, it requests magnetic measurements in at least two directions, for example, rolling and transverse directions

  20. Exclusive $\\omega$ meson muoproduction on transversely polarised protons

    CERN Document Server

    Adolph, C.; Aghasyan, M.; Akhunzyanov, R.; Alexeev, M.G.; Alexeev, G.D.; Amoroso, A.; Andrieux, V.; Anfimov, N.V.; Anosov, V.; Augustyniak, W.; Austregesilo, A.; Azevedo, C.D.R.; Badelek, B.; Balestra, F.; Barth, J.; Beck, R.; Bedfer, Y.; Bernhard, J.; Bicker, K.; Bielert, E.R.; Birsa, R.; Bisplinghoff, J.; Bodlak, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Buechele, M.; Chang, W. -C.; Chatterjee, C.; Chiosso, M.; Choi, I.; Chung, S. -U.; Cicuttin, A.; Crespo, M.L.; Curiel, Q.; Dalla Torre, S.; Dasgupta, S.S.; Dasgupta, S.; Denisov, O. Yu.; Dhara, L.; Donskov, S.V.; Doshita, N.; Duic, V.; Duennweber, W.; Dziewiecki, M.; Efremov, A.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; Fischer, H.; Franco, C.; von Hohenesche, N. du Fresne; Friedrich, J.M.; Frolov, V.; Fuchey, E.; Gautheron, F.; Gavrichtchouk, O.P.; Gerassimov, S.; Giordano, F.; Gnesi, I.; Gorzellik, M.; Grabmueller, S.; Grasso, A.; Grosse Perdekamp, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; Hahne, D.; von Harrach, D.; Hashimoto, R.; Heinsius, F.H.; Heitz, R.; Herrmann, F.; Hinterberger, F.; Horikawa, N.; dHose, N.; Hsieh, C. -Y.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Joosten, R.; Joerg, P.; Kabuss, E.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koivuniemi, J.H.; Kolosov, V.N.; Kondo, K.; Koenigsmann, K.; Konorov, I.; Konstantinov, V.F.; Kotzinian, A.M.; Kouznetsov, O.M.; Kraemer, M.; Kremser, P.; Krinner, F.; Kroumchtein, Z.V.; Kulinich, Y.; Kunne, F.; Kurek, K.; Kurjata, R.P.; Lednev, A.A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lian, Y. -S.; Lichtenstadt, J.; Longo, R.; Maggiora, A.; Magnon, A.; Makins, N.; Makke, N.; Mallot, G.K.; Marchand, C.; Marianski, B.; Martin, A.; Marzec, J.; Matousek, J.; Matsuda, H.; Matsuda, T.; Meshcheryakov, G.V.; Meyer, M.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Mikhasenko, M.; Mitrofanov, E.; Mitrofanov, N.; Miyachi, Y.; Montuenga, P.; Nagaytsev, A.; Nerling, F.; Neyret, D.; Nikolaenko, V.I.; Novy, J.; Nowak, W.D.; Nukazuka, G.; Nunes, A.S.; Olshevsky, A.G.; Orlov, I.; Ostrick, M.; Panzieri, D.; Parsamyan, B.; Paul, S.; Peng, J. -C.; Pereira, F.; Pesek, M.; Peshekhonov, D.V.; Pierre, N.; Platchkov, S.; Pochodzalla, J.; Polyakov, V.A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Riedl, C.; Roskot, M.; Ryabchikov, D.I.; Rybnikov, A.; Rychter, A.; Salac, R.; Samoylenko, V.D.; Sandacz, A.; Santos, C.; Sarkar, S.; Savin, I.A.; Sawada, T.; Sbrizzai, G.; Schiavon, P.; Schmidt, K.; Schmieden, H.; Schoenning, K.; Schopferer, S.; Seder, E.; Selyunin, A.; Shevchenko, O. Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Smolik, J.; Sozzi, F.; Srnka, A.; Steffen, D.; Stolarski, M.; Sulc, M.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Tasevsky, M.; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Tosello, F.; Tskhay, V.; Uhl, S.; Veloso, J.; Virius, M.; Vondra, J.; Wallner, S.; Weisrock, T.; Wilfert, M.; ter Wolbeek, J.; Zaremba, K.; Zavada, P.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.

    2017-01-01

    Exclusive production of $\\omega$ mesons was studied at the COMPASS experiment by scattering $160~\\mathrm{GeV}/\\mathit{c}$ muons off transversely polarised protons. Five single-spin and three double-spin azimuthal asymmetries were measured in the range of photon virtuality $1~(\\mathrm{GeV}/\\mathit{c})^2 < Q^2 < 10~(\\mathrm{GeV}/\\mathit{c})^2$, Bjorken scaling variable $0.003 < x_{\\mathit{Bj}} < 0.3$ and transverse momentum squared of the $\\omega$ meson $0.05~(\\mathrm{GeV}/\\mathit{c})^2 < p_{T}^{2} < 0.5~(\\mathrm{GeV}/\\mathit{c})^2$. The measured asymmetries are sensitive to the nucleon helicity-flip Generalised Parton Distributions (GPD) $E$ that are related to the orbital angular momentum of quarks, the chiral-odd GPDs $H_{T}$ that are related to the transversity Parton Distribution Functions, and the sign of the $\\pi\\omega$ transition form factor. The results are compared to recent calculations of a GPD-based model.

  1. Exclusive ω meson muoproduction on transversely polarised protons

    Directory of Open Access Journals (Sweden)

    C. Adolph

    2017-02-01

    Full Text Available Exclusive production of ω mesons was studied at the COMPASS experiment by scattering 160 GeV/c muons off transversely polarised protons. Five single-spin and three double-spin azimuthal asymmetries were measured in the range of photon virtuality 1 (GeV/c2

  2. Polarisation of Social Inequalities in Disadvantaged Neighbourhoods of Bucharest Metropolis

    Directory of Open Access Journals (Sweden)

    ALINA T. CHICOŞ

    2013-01-01

    Full Text Available This paper gives an insight into the statistical interpretation of socio-spatial changes of Bucharest urban landscape in connection to the transformations of the urban planning visions across the last decades. Special emphasis is placed on the emergence of disadvantaged neighbourhoods which are defined by a clear homogenisation of certain social classes on a precarious housing infrastructure. This came as a result of a historical hierarchy of the urban social space. Moreover, Bucharest was shaped in relation to different socio-economic and socio-cultural policies that determined the creation of a polarisation between north and south or between centre and periphery which were subject to numerous socio-urban inversions during the communist and post-communist eras. Hence, life in a large metropolis is vulnerable to inequalities appearing within the urban pattern that intensifies, in some cases, towards residential segregation. The historical-geographical analysis of vectors behind clusters of sensitive areas in the 20th and 21st centuries strengthens the importance of social cohesion measures in the future urban policies and territorial planning.

  3. A new class of spontaneously polarized materials

    DEFF Research Database (Denmark)

    Field, David; Plekan, Oksana; Cassidy, Andrew

    2011-01-01

    Very large electric fields form spontaneously within films of seemingly prosaic chemicals such as nitrous oxide or propane.We describe how the discovery of this unexpected phenomenon took place and how we attempt to understand the nature of the new class of spontaneously polarized materials...

  4. Spontaneous baryogenesis from asymmetric inflaton

    International Nuclear Information System (INIS)

    Takahashi, Fuminobu

    2015-10-01

    We propose a variant scenario of spontaneous baryogenesis from asymmetric inflaton based on current-current interactions between the inflaton and matter fields with a non-zero B-L charge. When the inflaton starts to oscillate around the minimum after inflation, it may lead to excitation of a CP-odd component, which induces an effective chemical potential for the B-L number through the current-current interactions. We study concrete inflation models and show that the spontaneous baryogenesis scenario can be naturally implemented in the chaotic inflation in supergravity.

  5. The pion polarisability and more measurements on chiral dynamics at COMPASS

    CERN Document Server

    Friedrich, Jan

    2016-01-01

    Within the physics program of the COMPASS experiment at CERN pion-photon reactions are measured via the Primakoff effect, referring to processes in which high-energetic pions react with the quasi-real photon field that surrounds the target nuclei. The production of a single hard photon in such a pion scattering at lowest momentum transfer to the nucleus is related to pion Compton scattering. From the measured cross-section shape, the pion polarisability has been determined, a result that has been published meanwhile as a Physical Review Letter [ 1 ]. The COMPASS measurement is in tension with the earlier dedicated measurements, and rather in agreement with the theoretical expectation from chiral perturbation theory. The analysis of a more recent high-statistics data taking is underway. Reactions with neutral and more charged pions in the final state are measured and analyzed as well. At low energy in the pion-photon centre-of-momentum system, these reactions are governed by chiral dynamics and contain informa...

  6. Studying the superconductor-ferromagnet proximity effect with polarised neutron reflectometry

    Science.gov (United States)

    Satchell, Nathan; Cooper, Joshaniel; Kinane, Christy; Witt, James; Burnell, Gavin; Langridge, Sean

    At the interface between a superconductor (S) and ferromagnet (F), an inhomogeneity can convert singlet Cooper pairs into the (spin aligned) long ranged triplet component (LRTC). The manipulation of the LRTC forms the basis of the emerging field of super-spintronics. Several theoretical works predict modification to the local magnetic state inside the S layer with the inclusion of triplet Cooper pairs, however there are now several experimental observations which disagree on both the magnitude and direction of this induced moment (see for example and). Here we report on measurements of the proximity effect using polarised neutron reflectometry, a technique sensitive to changes in the total magnetisation of a S-F heterostructure. Our results suggest that a `smoking gun' direct signature of the LRTC is below the sensitivity of our technique, we are able to study the inverse effect namely a modification to the ferromagnetism by proximity to singlet superconductivity. These observations are supported by XMCD measurements showing changes to the Fe and Co below the S layer Tc.

  7. IMPROVING IMAGE MATCHING BY REDUCING SURFACE REFLECTIONS USING POLARISING FILTER TECHNIQUES

    Directory of Open Access Journals (Sweden)

    N. Conen

    2018-05-01

    Full Text Available In dense stereo matching applications surface reflections may lead to incorrect measurements and blunders in the resulting point cloud. To overcome the problem of disturbing reflexions polarising filters can be mounted on the camera lens and light source. Reflections in the images can be suppressed by crossing the polarising direction of the filters leading to homogeneous illuminated images and better matching results. However, the filter may influence the camera’s orientation parameters as well as the measuring accuracy. To quantify these effects, a calibration and an accuracy analysis is conducted within a spatial test arrangement according to the German guideline VDI/VDE 2634.1 (2002 using a DSLR with and without polarising filter. In a second test, the interior orientation is analysed in more detail. The results do not show significant changes of the measuring accuracy in object space and only very small changes of the interior orientation (Δc ≤ 4 μm with the polarising filter in use. Since in medical applications many tiny reflections are present and impede robust surface measurements, a prototypic trinocular endoscope is equipped with polarising technique. The interior and relative orientation is determined and analysed. The advantage of the polarising technique for medical image matching is shown in an experiment with a moistened pig kidney. The accuracy and completeness of the resulting point cloud can be improved clearly when using polarising filters. Furthermore, an accuracy analysis using a laser triangulation system is performed and the special reflection properties of metallic surfaces are presented.

  8. Spontaneous emission by moving atoms

    International Nuclear Information System (INIS)

    Meystre, P.; Wilkens, M.

    1994-01-01

    It is well known that spontaneous emission is not an intrinsic atomic property, but rather results from the coupling of the atom to the vacuum modes of the electromagnetic field. As such, it can be modified by tailoring the electromagnetic environment into which the atom can radiate. This was already realized by Purcell, who noted that the spontaneous emission rate can be enhanced if the atom placed inside a cavity is resonant with one of the cavity is resonant with one of the cavity modes, and by Kleppner, who discussed the opposite case of inhibited spontaneous emission. It has also been recognized that spontaneous emission need not be an irreversible process. Indeed, a system consisting of a single atom coupled to a single mode of the electromagnetic field undergoes a periodic exchange of excitation between the atom and the field. This periodic exchange remains dominant as long as the strength of the coupling between the atom and a cavity mode is itself dominant. 23 refs., 6 figs

  9. Statistical properties of intensity of partially polarised semiconductor laser light backscattered by a single-mode optical fibre

    International Nuclear Information System (INIS)

    Alekseev, A E; Potapov, V T; Gorshkov, B G

    2015-01-01

    We report the results of studying statistical properties of the intensity of partially polarised coherent light backscattered by a single mode optical fibre. An expression is derived for the deviation of the backscattered light intensity depending on the scattering region length, the degree of the light source coherence and the degree of scattered light polarisation. It is shown that the backscattered light in a fibre scattered-light interferometer is partially polarised with the polarisation degree P = 1/3 in the case of external perturbations of the interferometer fibre. (scattering of light)

  10. Determination of the gluon polarisation from open charm production at COMPASS

    CERN Document Server

    Koblitz, Susanne

    2009-01-01

    One of the main goals of the COMPASS experiment at CERN is the determination of the gluon polarisation in the nucleon. It is determined from spin asymmetries in the scattering of 160 GeV/c polarised muons on a polarised LiD target. The gluon polarisation is accessed by the selection of photon-gluon fusion (PGF) events. The PGF-process can be tagged through hadrons with high transverse momenta or through charmed hadrons in the final state. The advantage of the open charm channel is that, in leading order, the PGF-process is the only process for charm production, thus no physical background contributes to the selected data sample. This thesis presents a measurement of the gluon polarisation from the COMPASS data taken in the years 2002-2004. In the analysis, charm production is tagged through a reconstructed D0-meson decaying in $D^{0}-> K^{-}pi^{+}$ (and charge conjugates). The reconstruction is done on a combinatorial basis. The background of wrong track pairs is reduced using kinematic cuts to the reconstruc...

  11. Measurement of {lambda} polarisation observables at the COSY-TOF spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Pizzolotto, C.

    2007-05-22

    In this work the (vector)pp {yields} pK{sup +}{lambda} reaction is studied. Data were taken at the COSY-TOF experiment in 2002 with a polarised proton beam at the momenta of 2.75 GeV/c and 2.95 GeV/c. The calculated beam polarisation was 39.8% and 61.9% respectively. The experimental setup covers the whole phase space of the reaction. The exclusive measurement allows the extraction of polarisation observables not only in the beam fragmentation region (x{sub F}>0), but also in the target fragmentation region (x{sub F} < 0). Samples of 11991 pK{sup +}{lambda} events at 2.75 GeV/c and of 19243 events at 2.95 GeV/c beam momentum have been reconstructed. The {lambda} polarisation, the {lambda} analysing power and the spin transfer coefficient were extracted. The {lambda} polarisation P{sub {lambda}} has a negative trend. The analysing power A{sup {lambda}}{sub y} and the spin transfer coefficient D{sub NN} are found to be compatible with zero. The measured spin transfer coefficient is in contradiction with the only result published up to now at comparable beam momenta. (orig.)

  12. Observations of the Polarisation of the Anomalous Microwave Emission: A Review

    Directory of Open Access Journals (Sweden)

    J. A. Rubiño-Martín

    2012-01-01

    Full Text Available The observational status of the polarisation of the anomalous microwave emission (AME is reviewed, both for individual compact Galactic regions as well as for the large-scale Galactic emission. There are six Galactic regions with existing polarisation constraints in the relevant range of 10–40 GHz: four dust clouds (Perseus, ρ Ophiuchi, LDN1622, and Pleiades and two HII regions (LPH96 and the Helix nebula. These constraints are discussed in detail and are complemented by deriving upper limits on the polarisation of the AME for those objects without published WMAP constraints. For the case of large-scale emission, two recent works, based on WMAP data, are reviewed. Currently, the best constraints on the fractional polarisation of the AME, at frequencies near the peak of the emission (i.e., 20–30 GHz, are at the level of ~1% (95.4% confidence level. Finally, we compare these constraints with the predictions of some theoretical AME models and discuss the possible impact of polarised AME on future primordial B-mode experiments.

  13. A physico-genetic module for the polarisation of auxin efflux carriers PIN-FORMED (PIN)

    Science.gov (United States)

    Hernández-Hernández, Valeria; Barrio, Rafael A.; Benítez, Mariana; Nakayama, Naomi; Romero-Arias, José Roberto; Villarreal, Carlos

    2018-05-01

    Intracellular polarisation of auxin efflux carriers is crucial for understanding how auxin gradients form in plants. The polarisation dynamics of auxin efflux carriers PIN-FORMED (PIN) depends on both biomechanical forces as well as chemical, molecular and genetic factors. Biomechanical forces have shown to affect the localisation of PIN transporters to the plasma membrane. We propose a physico-genetic module of PIN polarisation that integrates biomechanical, molecular, and cellular processes as well as their non-linear interactions. The module was implemented as a discrete Boolean model and then approximated to a continuous dynamic system, in order to explore the relative contribution of the factors mediating PIN polarisation at the scale of single cell. Our models recovered qualitative behaviours that have been experimentally observed and enable us to predict that, in the context of PIN polarisation, the effects of the mechanical forces can predominate over the activity of molecular factors such as the GTPase ROP6 and the ROP-INTERACTIVE CRIB MOTIF-CONTAINING PROTEIN RIC1.

  14. Group theory of spontaneous symmetry breaking

    International Nuclear Information System (INIS)

    Ghaboussi, F.

    1987-01-01

    The connection between the minimality of the Higgs field potential and the maximal little groups of its representation obtained by spontaneous symmetry breaking is analyzed. It is shown that for several representations the lowest minimum of the potential is related to the maximal little group of those representations. Furthermore, a practical necessity criterion is given for the representation of the Higgs field needed for spontaneous symmetry breaking

  15. Radio-continuum observations of small, radially polarised Supernova Remnant J0519-6902 in the large Magellanic cloud

    Directory of Open Access Journals (Sweden)

    Bozzetto L.M.

    2012-01-01

    Full Text Available We report on new Australian Telescope Compact Array (ATCA observations of SNR J0519-6902. The Supernova Remnant (SNR is small in size (~8 pc and exhibits a typical SNR spectrum with α = -0.53±0.07, with steeper spectral indices towards the northern limb of the remnant. SNR J0519-6902 contains a low level of radially orientated polarisation at wavelengths of 3 and 6 cm, which is typical of younger SNRs. A fairly strong magnetic field was estimated to ~171µG. The remnant appears to be the result of a typical Type Ia supernova, sharing many properties with another small and young Type Ia LMC SNR, J0509-6731. [Projekat Ministarstva nauke Republike Srbije, br. 176005

  16. Circular polarisation: a new probe of dark matter and neutrinos in the sky

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, Céline [Institute for Particle Physics Phenomenology, Durham University, South Road, Durham, DH1 3LE (United Kingdom); Degrande, Céline [CERN, Theory Division, Geneva 23 CH-1211 (Switzerland); Mattelaer, Olivier [Center for Cosmology, Particle Physics and Phenomenology, Université Catholique de Louvain, Chemin du cyclotron, 2 1348 Louvain-La-Neuve Belgium (Belgium); Vincent, Aaron C., E-mail: c.m.boehm@durham.ac.uk, E-mail: celine.degrande@cern.ch, E-mail: olivier.mattelaer@uclouvain.be, E-mail: aaron.vincent@imperial.ac.uk [Department of Physics, Imperial College London, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom)

    2017-05-01

    The study of anomalous electromagnetic emission in the sky is the basis of indirect searches for dark matter. It is also a powerful tool to constrain the radiative decay of active neutrinos. Until now, quantitative analyses have focused on the flux and energy spectrum of such an emission; polarisation has never been considered. Here we show that we could be missing out on an essential piece of information. The radiative decay of neutrinos, as well as the interactions of dark matter and neutrinos with Standard Model particles can generate a circular polarisation signal in X-rays or γ-rays. If observed, this could reveal important information about their spatial distribution and particle-antiparticle ratio, and could even reveal the nature of the high-energy particle physics processes taking place in astrophysical sites. The question of the observability of these polarised signatures and their separation from background astrophysical sources is left for future work.

  17. Propagation of polarised light in bent hi-bi spun fibres

    Energy Technology Data Exchange (ETDEWEB)

    Przhiyalkovsky, Ya V; Morshnev, S K; Starostin, N I; Gubin, V P [V.A.Kotel' nikov Institute of Radio Engineering and Electronics, Russian Academy of Sciences, Fryazino branch, Fryazino, Moscow Region (Russian Federation)

    2015-11-30

    The evolution of polarisation states (PS's) of broadband light propagating through a bent optical fibre with a helical structure of its refractive index anisotropy (hi-bi spun fibre) has been studied theoretically and experimentally. It has been shown that there exists a coordinate system of PS's in which the differential Jones matrix can be replaced by a diagonal matrix, which allows the polarisation parameters of the output broadband light to be readily calculated with sufficient accuracy. We have derived a formula for evaluating the magneto-optical sensitivity of a bent spun fibre. An approach has been proposed for restoring the degree of polarisation of light in a bent hi-bi spun fibre and, as a consequence, the visibility (contrast) of the interferometer in a current sensor with a sensing element based on the fibre under consideration. (optical fibres)

  18. Polarisation-sensitive switch: An integrated intensity-independent solution for 1.3 μm based on the polarisation anisotropy of ordered InGaAsP

    International Nuclear Information System (INIS)

    Kraemer, S.; Malzer, S.; Doehler, G.H.; Neumann, S.; Prost, W.; Tegude, F.J.

    2005-01-01

    Ordered materials provide new possibilities for optical device applications. Through a strong polarisation anisotropy of absorption a high functional polarisation-sensitive switch can be fabricated which in addition is nearly independent on the optical power. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. Polarised two-photon excitation of quantum well excitons for manipulation of optically pumped terahertz lasers

    Energy Technology Data Exchange (ETDEWEB)

    Slavcheva, G., E-mail: gsk23@bath.ac.uk [Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2AZ (United Kingdom); Kavokin, A.V., E-mail: A.Kavokin@soton.ac.uk [School of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Spin Optics Laboratory, St. Petersburg State University, 1, Ulyanovskaya 198504 (Russian Federation)

    2014-11-15

    Optical pumping of excited exciton states in a semiconductor quantum well embedded in a microcavity is a tool for realisation of ultra-compact terahertz (THz) lasers based on stimulated optical transition between excited (2p) and ground (1s) exciton state. We show that the probability of two-photon absorption by a 2p-exciton is strongly dependent on the polarisation of both pumping photons. Five-fold variation of the threshold power for terahertz lasing by switching from circular to co-linear pumping is predicted. We identify photon polarisation configurations for achieving maximum THz photon generation quantum efficiency.

  20. Measurement of recoil photon polarisation in the electron-proton elastic scattering

    International Nuclear Information System (INIS)

    Buon, Jean

    1965-02-01

    This research thesis reports and discusses an experiment which aimed at checking the validity of the Born approximation at the first order in the elastic scattering of high energy electrons on protons. In this experiment, the recoil proton polarisation is measured in an elastic scattering of electrons with energy of 950 MeV and scattering at about 90 degrees in the mass centre system. The author describes the experimental installation, its operation and data collection, reports the analysis of photos and polarisation calculations and errors [fr

  1. First measurement of charged current cross sections at HERA with longitudinally polarised positrons

    Science.gov (United States)

    H1 Collaboration; Aktas, A.; Andreev, V.; Anthonis, T.; Antunovic, B.; Aplin, S.; Asmone, A.; Astvatsatourov, A.; Babaev, A.; Backovic, S.; Bähr, J.; Baghdasaryan, A.; Baranov, P.; Barrelet, E.; Bartel, W.; Baudrand, S.; Baumgartner, S.; Becker, J.; Beckingham, M.; Behnke, O.; Behrendt, O.; Belousov, A.; Berger, Ch.; Berger, N.; Bizot, J. C.; Boenig, M.-O.; Boudry, V.; Bracinik, J.; Brandt, G.; Brisson, V.; Bruncko, D.; Büsser, F. W.; Bunyatyan, A.; Buschhorn, G.; Bystritskaya, L.; Campbell, A. J.; Cassol-Brunner, F.; Cerny, K.; Cerny, V.; Chekelian, V.; Contreras, J. G.; Coughlan, J. A.; Cox, B. E.; Cozzika, G.; Cvach, J.; Dainton, J. B.; Dau, W. D.; Daum, K.; de Boer, Y.; Delcourt, B.; Del Degan, M.; de Roeck, A.; Desch, K.; de Wolf, E. A.; Diaconu, C.; Dodonov, V.; Dubak, A.; Eckerlin, G.; Efremenko, V.; Egli, S.; Eichler, R.; Eisele, F.; Elsen, E.; Erdmann, W.; Essenov, S.; Falkewicz, A.; Faulkner, P. J. W.; Favart, L.; Fedotov, A.; Feltesse, J.; Ferencei, J.; Finke, L.; Fleischer, M.; Fleischmann, P.; Flucke, G.; Fomenko, A.; Foresti, I.; Franke, G.; Frisson, T.; Gabathuler, E.; Garutti, E.; Gayler, J.; Gerlich, C.; Ghazaryan, S.; Ginzburgskaya, S.; Glazov, A.; Glushkov, I.; Goerlich, L.; Goettlich, M.; Gogitidze, N.; Gorbounov, S.; Goyon, C.; Grab, C.; Greenshaw, T.; Gregori, M.; Grell, B. R.; Grindhammer, G.; Gwilliam, C.; Haidt, D.; Hajduk, L.; Hansson, M.; Heinzelmann, G.; Henderson, R. C. W.; Henschel, H.; Herrera, G.; Hildebrandt, M.; Hiller, K. H.; Hoffmann, D.; Horisberger, R.; Hovhannisyan, A.; Hreus, T.; Hussain, S.; Ibbotson, M.; Ismail, M.; Jacquet, M.; Janauschek, L.; Janssen, X.; Jemanov, V.; Jönsson, L.; Johnson, D. P.; Jung, A. W.; Jung, H.; Kapichine, M.; Katzy, J.; Kenyon, I. R.; Kiesling, C.; Klein, M.; Kleinwort, C.; Klimkovich, T.; Kluge, T.; Knies, G.; Knutsson, A.; Korbel, V.; Kostka, P.; Krastev, K.; Kretzschmar, J.; Kropivnitskaya, A.; Krüger, K.; Kückens, J.; Landon, M. P. J.; Lange, W.; Laštovička, T.; Laštovička-Medin, G.; Laycock, P.; Lebedev, A.; Leibenguth, G.; Lendermann, V.; Levonian, S.; Lindfeld, L.; Lipka, K.; Liptaj, A.; List, B.; List, J.; Lobodzinska, E.; Loktionova, N.; Lopez-Fernandez, R.; Lubimov, V.; Lucaci-Timoce, A.-I.; Lueders, H.; Lüke, D.; Lux, T.; Lytkin, L.; Makankine, A.; Malden, N.; Malinovski, E.; Mangano, S.; Marage, P.; Marshall, R.; Martisikova, M.; Martyn, H.-U.; Maxfield, S. J.; Meer, D.; Mehta, A.; Meier, K.; Meyer, A. B.; Meyer, H.; Meyer, J.; Michels, V.; Mikocki, S.; Milcewicz-Mika, I.; Milstead, D.; Mladenov, D.; Mohamed, A.; Moreau, F.; Morozov, A.; Morris, J. V.; Mozer, M. U.; Müller, K.; Murín, P.; Nankov, K.; Naroska, B.; Naumann, Th.; Newman, P. R.; Niebuhr, C.; Nikiforov, A.; Nowak, G.; Nozicka, M.; Oganezov, R.; Olivier, B.; Olsson, J. E.; Osman, S.; Ozerov, D.; Palichik, V.; Panagoulias, I.; Papadopoulou, T.; Pascaud, C.; Patel, G. D.; Peng, H.; Perez, E.; Perez-Astudillo, D.; Perieanu, A.; Petrukhin, A.; Pitzl, D.; Plačakytė, R.; Portheault, B.; Povh, B.; Prideaux, P.; Rahmat, A. J.; Raicevic, N.; Reimer, P.; Reisert, B.; Rimmer, A.; Risler, C.; Rizvi, E.; Robmann, P.; Roland, B.; Roosen, R.; Rostovtsev, A.; Rurikova, Z.; Rusakov, S.; Salvaire, F.; Sankey, D. P. C.; Sauvan, E.; Schätzel, S.; Schmidt, S.; Schmitt, S.; Schmitz, C.; Schoeffel, L.; Schöning, A.; Schultz-Coulon, H.-C.; Sedlák, K.; Sefkow, F.; Shaw-West, R. N.; Sheviakov, I.; Shtarkov, L. N.; Sloan, T.; Smirnov, P.; Soloviev, Y.; South, D.; Spaskov, V.; Specka, A.; Steder, M.; Stella, B.; Stiewe, J.; Strauch, I.; Straumann, U.; Sunar, D.; Tchoulakov, V.; Thompson, G.; Thompson, P. D.; Tomasz, F.; Traynor, D.; Truöl, P.; Tsakov, I.; Tsipolitis, G.; Tsurin, I.; Turnau, J.; Tzamariudaki, E.; Urban, K.; Urban, M.; Usik, A.; Utkin, D.; Valkárová, A.; Vallée, C.; van Mechelen, P.; Vargas Trevino, A.; Vazdik, Y.; Veelken, C.; Vinokurova, S.; Volchinski, V.; Wacker, K.; Wagner, J.; Weber, G.; Weber, R.; Wegener, D.; Werner, C.; Wessels, M.; Wessling, B.; Wigmore, C.; Wissing, Ch.; Wolf, R.; Wünsch, E.; Xella, S.; Yan, W.; Yeganov, V.; Žáček, J.; Zálešák, J.; Zhang, Z.; Zhelezov, A.; Zhokin, A.; Zhu, Y. C.; Zimmermann, J.; Zimmermann, T.; Zohrabyan, H.; Zomer, F.

    2006-03-01

    Data taken with positrons of different longitudinal polarisation states in collision with unpolarised protons at HERA are used to measure the total cross sections of the charged current process, ep→ν¯X, for negative four-momentum transfer squared Q>400 GeV and inelasticity y<0.9. Together with the corresponding cross section obtained from the previously published unpolarised data, the polarisation dependence of the charged current cross section is measured for the first time at high Q and found to be in agreement with the Standard Model prediction.

  2. Erratum: Correction to: Polarisation vision: overcoming challenges of working with a property of light we barely see

    Science.gov (United States)

    Foster, James J.; Temple, Shelby E.; How, Martin J.; Daly, Ilse M.; Sharkey, Camilla R.; Wilby, David; Roberts, Nicholas W.

    2018-06-01

    In "Polarisation vision: overcoming challenges of working with a property of light we barely see" (Foster et al. 2018) we provide a basic description of how Stokes parameters can be estimated and used to calculate the angle of polarisation (AoP).

  3. Measuring the corrosion rate of steel in concrete – effect of measurement technique, polarisation time and current

    DEFF Research Database (Denmark)

    Nygaard, Peter Vagn; Geiker, Mette Rica

    2012-01-01

    , are in some studies considered the main reasons for the variations. This paper presents an experimental study on the quantitative effect of polarisation time and current on the measured polarisation resistance – and thus the corrosion current density – of passively and actively corroding steel. Two...... electrochemical techniques often used in instruments for on-site corrosion rate measurements are investigated. On passively corroding reinforcement the measured polarisation resistance was for both techniques found to be highly affected by the polarisation time and current and no plateaus at either short or long...... rate for actively corroding steel. For both techniques guidelines for polarisation times and currents are given for (on-site) non-destructive corrosion rate measurements on reinforcement steel in concrete....

  4. Spontaneous external gallbladder perforation

    International Nuclear Information System (INIS)

    Noeldge, G.; Wimmer, B.; Kirchner, R.

    1981-01-01

    Spontaneous perforation of the gallbladder is one complication of cholelithiasis. There is a greater occurence of free perforation in the peritoneal cavity with bilary pertonitis, followed by the perforation into the stomach, small intestine and colon. A single case of the nowadays rare spontaneous perforation in and through the abdominal wall will be reported. Spontaneous gallbladder perforation appears nearly asymptomatic in its clinical course because of absent biliary peritonitis. (orig.) [de

  5. Peritonitis - spontaneous bacterial

    Science.gov (United States)

    Spontaneous bacterial peritonitis (SBP); Ascites - peritonitis; Cirrhosis - peritonitis ... who are on peritoneal dialysis for kidney failure. Peritonitis may have other causes . These include infection from ...

  6. Comparison between time-and frequency-domain induced polarisation parameters

    CSIR Research Space (South Africa)

    Van Schoor, Abraham M

    2009-09-01

    Full Text Available of mineralised rocks and of the contrast between different rock types. It is further shown that a multi-frequency (spectral) approach can be used to avoid this pitfall; similarly, the calculation of different time-domain induced polarisation (IP) parameters...

  7. Variable and Polarised Near-infrared Emission from the Galactic Centre

    Czech Academy of Sciences Publication Activity Database

    Shahzamanian, B.; Eckart, A.; Valencia-S, M.; Witzel, G.; Zamaninasab, M.; Zajaček, Michal; Sabha, N.; García-Marín, M.; Karas, Vladimír; Peissker, F.; Karssen, G.; Parsa, M.; Grosso, N.; Mossoux, E.; Porquet, D.; Jalali, B.; Horrobin, M.; Buchholz, R. M.; Dovčiak, Michal; Kunneriath, Devaky; Bursa, Michal; Zensus, A.; Schödel, R.; Moultaka, J.; Straubmeier, C.

    2015-01-01

    Roč. 159, March (2015), s. 41-45 ISSN 0722-6691 Grant - others:EU(XE) COST Action MP0905; EU(XE) COST action MP1104; DAAD(DE) DAAD-15-14 Program:Bilaterální spolupráce Institutional support: RVO:67985815 Keywords : polarisation effects * galactic center * observations Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics

  8. Gluon polarisation in the nucleon and longitudinal double spin asymmetries from open charm muoproduction

    Czech Academy of Sciences Publication Activity Database

    Alekseev, M.; Alexakhin, V. Yu.; Alexandrov, Yu.; Alexeev, G. D.; Amoroso, A.; Austregisilio, A.; Badelek, B.; Balestra, F.; Ball, J.; Barth, J.; Baum, G.; Bedfer, Y.; Bernhard, J.; Bertini, R.; Bettinelli, M.; Birsa, R.; Bisplinghoff, J.; Bordalo, P.; Bradamante, F.; Bravar, A.; Bressan, A.; Brona, G.; Burtin, E.; Bussa, M.; Chapiro, A.; Chiosso, M.; Chung, S.U.; Cicuttin, A.; Colantoni, M.; Crespo, M.; Dalla Torre, S.; Dafni, T.; Das, S.; Dasgupta, S. S.; Denisov, O.; Dhara, L.; Diaz, V.; Dinkelbach, A.; Donskov, S.; Doshita, N.; Duic, V.; Dünnweber, W.; Efremov, A.V.; El Alaoui, A.; Eversheim, P.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; Finger jr., M.; Fischer, H.; Franco, C.; Friedrich, J.; Garfagnini, R.; Gautheron, F.; Gavrichtchouk, O.; Gazda, R.; Gerassimov, S.; Geyer, R.; Giorgi, M.; Gobbo, B.; Goertz, S.; Grabmüller, S.; Grajek, O.; Grasso, A.; Grube, B.; Gushterski, R.; Guskov, A.; Haas, F.; Hagemann, R.; von Harrach, D.; Hasegawa, T.; Heckmann, J.; Heinsius, F.; Hermann, R.; Herrmann, F.; Hess, C.; Hinterberger, F.; von Hodenberg, M.; Horikawa, N.; Höppner, Ch.; d'Hose, N.; Ilgner, C.; Ishimoto, S.; Ivanov, O.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jasinski, P.; Jegou, G.; Joosten, R.; Kabuss, E.; Käfer, W.; Kang, D.; Ketzer, B.; Khaustov, G.; Khokhlov, Y.; Kiefer, J.; Kisselev, Y.; Klein, F.; Klimaszewski, K.; Koblitz, S.; Koivuniemi, J.; Kolosov, V.; Komissarov, E.; Kondo, K.; Königsmann, K.; Konorov, I.; Konstantinov, V.; Korzenev, A.; Kotzinian, A.; Kouznetsov, O.; Kowalik, K.; Krämer, M.; Kral, A.; Kroumchtein, Z.; Kuhn, R.; Kunne, F.; Kurek, K.; Le Goff, J.; Lednev, A.; Lehmann, A.; Levorato, S.; Lichtenstadt, J.; Liska, T.; Maggiora, A.; Maggiora, M.; Magnon, A.; Mallot, G.; Mann, A.; Marchand, C.; Marroncle, J.; Martin, A.; Marzec, J.; Massmann, F.; Matsuda, T.; Maximov, A.; Meyer, W.; Michigami, T.; Mikhailov, Y.; Moinester, M.; Mutter, A.; Nagaytsev, A.; Nagel, T.; Nassalski, J.; Negrini, S.; Nerling, F.; Neubert, S.; Neyret, D.; Nikolaenko, V.; Olshevsky, A.; Ostrick, M.; Padee, A.; Panebianco, S.; Panknin, R.; Panzieri, D.; Parsamyan, B.; Paul, S.; Pawlukiewicz-Kaminska, B.; Perevalova, E.; Pesaro, G.; Peshekhonov, D.; Piragino, G.; Platchkov, S.; Pochodzalla, J.; Polak, J.; Polyakov, V.; Pontecorvo, G.; Pretz, J.; Quintans, C.; Rajotte, J.; Ramos, S.; Rapatsky, V.; Reicherz, G.; Reggiani, D.; Richter, A.; Robinet, F.; Rocco, E.; Rondio, E.; Ryabchikov, D.; Samoylenko, V.; Sandacz, A.; Santos, H.; Sapozhnikov, M.; Sarkar, S.; Savin, I.; Sbrizzai, G.; Schiavon, P.; Schill, C.; Schmitt, L.; Schröder, W.; Shevchenko, O.; Siebert, H.; Silva, L.; Sinha, L.; Sissakian, A.; Slunecka, M.; Smirnov, G.; Sosio, S.; Sozzi, F.; Srnka, Aleš; Stolarski, M.; Sulc, M.; Sulej, R.; Takekawa, S.; Tessaro, S.; Tessarotto, F.; Teufel, A.; Tkatchev, L.; Venugopal, G.; Virius, M.; Vlassov, N.; Vossen, A.; Weitzel, Q.; Wenzl, K.; Windmolders, R.; Wislicki, W.; Wollny, H.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zhao, J.; Zhuravlev, N.; Zvyagin, A.

    2009-01-01

    Roč. 676, 1-3 (2009), s. 31-38 ISSN 0370-2693 R&D Projects: GA MŠk ME 492 Institutional research plan: CEZ:AV0Z20650511 Keywords : inelastic muon scattering * spin * asymmetry * gluon polarisation Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 5.083, year: 2009

  9. First doubly polarised photoproduction on 3He at the photon beam of MAMI

    International Nuclear Information System (INIS)

    Aguar Bartolome, Patricia

    2010-11-01

    A first experiment with a polarised 3 He target was carried out in July 2009 at the MAMI accelerator in Mainz in a photon energy range between 200 MeV and 800 MeV. The aim of this measurement was to investigate the Gerasimov-Drell-Hearn sum rule on the neutron. The use of the data obtained with the polarised 3 He target, compared to existing data on the deuteron, gives a complementary and more direct access to the neutron, due to the spin structure of the 3 He. The measurement of the helicity dependence of the inclusive total photoabsorption cross section required a beam of tagged circularly polarised photons incident on the longitudinally polarised 3 He target. The data were taken using the 4π Crystal Ball photon spectrometer in combination with TAPS as a forward wall and complemented by a threshold Cherenkov detector used to on-line suppress the background from electromagnetic events. The development and preparation of the different components of the 3 He experimental setup was an important part of this work and are described in detail in this thesis. The detector system and the analysis method were tested by the measurement of the unpolarised total inclusive photoabsorption cross section on liquid hydrogen. The results obtained are in good agreement with previous published data. Preliminary results of the unpolarised total photoabsorption cross section, as well as the helicity dependent photoabsorption cross section difference on 3 He compared with several theoretical models will also be presented. (orig.)

  10. Effects of the particle spin polarisation on the unstable modes in the ...

    Indian Academy of Sciences (India)

    Hengameh Khanzadeh

    2017-12-20

    Dec 20, 2017 ... cross-section compared to the fusion interaction cross- section [10]. The impact of the particle spin polarisation on the electromagnetic instabilities present in the veloc- ity space depends on the electromagnetic instabilities. The basic theory will be introduced initially according to two different kinetic models ...

  11. EFA6 regulates selective polarised transport and axon regeneration from the axon initial segment

    Czech Academy of Sciences Publication Activity Database

    Eva, R.; Koseki, H.; Kanamarlapudi, V.; Fawcett, James

    2017-01-01

    Roč. 130, č. 21 (2017), s. 3663-3675 ISSN 0021-9533 Institutional support: RVO:68378041 Keywords : axon regeneration * axon transport * neuronal polarisation Subject RIV: FH - Neurology OBOR OECD: Neuroscience s (including psychophysiology Impact factor: 4.431, year: 2016

  12. Very high coupling of TM polarised light in photonic crystal directional couplers

    DEFF Research Database (Denmark)

    Borel, Peter Ingo; Thorhauge, Morten; Frandsen, Lars Hagedorn

    2003-01-01

    The experimental and simulated spectra for TE and TM polarised light for the transmission through photonic crystal directional couplers are presented. The 3D FDTD simulations successfully explain all the major features of the experimental spectra as well as the actual transmission level. Especially...

  13. Leading-order determination of the gluon polarisation from semi-inclusive deep inelastic scattering data

    CERN Document Server

    Adolph, C.; Akhunzyanov, R.; Alexeev, M.G.; Alexeev, G.D.; Amoroso, A.; Andrieux, V.; Anfimov, N.V.; Anosov, V.; Augustyniak, W.; Austregesilo, A.; Azevedo, C.D.R.; Badelek, B.; Balestra, F.; Barth, J.; Beck, R.; Bedfer, Y.; Bernhard, J.; Bicker, K.; Bielert, E.R.; Birsa, R.; Bisplinghoff, J.; Bodlak, M.; Boer, M.; Bordalo, P.; Bradamante, F.; Braun, C.; Bressan, A.; Buchele, M.; Chang, W.C.; Chiosso, M.; Choi, I.; Chung, S.U.; Cicuttin, A.; Crespo, M.L.; Curiel, Q.; Dalla Torre, S.; Dasgupta, S.S.; Dasgupta, S.; Denisov, O.Yu.; Dhara, L.; Donskov, S.V.; Doshita, N.; Duic, V.; Dunnweber, W.; Dziewiecki, M.; Efremov, A.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; M. Finger jr; Fischer, H.; Franco, C.; von Hohenesche, N. du Fresne; Friedrich, J.M.; Frolov, V.; Fuchey, E.; Gautheron, F.; Gavrichtchouk, O.P.; Gerassimov, S.; Giordano, F.; Gnesi, I.; Gorzellik, M.; Grabmuller, S.; Grasso, A.; Grosse Perdekamp, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; Hahne, D.; von Harrach, D.; Hashimoto, R.; Heinsius, F.H.; Heitz, R.; Herrmann, F.; Hinterberger, F.; Horikawa, N.; d'Hose, N.; Hsieh, C.Y.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; Joosten, R.; Jorg, P.; Kabuss, E.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu. A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koivuniemi, J.H.; Kolosov, V.N.; Kondo, K.; Konigsmann, K.; Konorov, I.; Konstantinov, V.F.; Kotzinian, A.M.; Kouznetsov, O.M.; Kramer, M.; Kremser, P.; Krinner, F.; Kroumchtein, Z.V.; Kulinich, Y.; Kunne, F.; Kurek, K.; Kurjata, R.P.; Lednev, A.A.; Lehmann, A.; Levillain, M.; Levorato, S.; Lichtenstadt, J.; Longo, R.; Maggiora, A.; Magnon, A.; Makins, N.; Makke, N.; Mallot, G.K.; Marchand, C.; Marianski, B.; Martin, A.; Marzec, J.; J.Matou s; Matsuda, H.; Matsuda, T.; Meshcheryakov, G.V.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Mikhasenko, M.; Miyachi, Y.; Montuenga, P.; Nagaytsev, A.; Nerling, F.; Neyret, D.; Nikolaenko, V.I.; Novy, J.; Nowak, W.D.; Nukazuka, G.; Nunes, A.S.; Olshevsky, A.G.; Orlov, I.; Ostrick, M.; Panzieri, D.; Parsamyan, B.; Paul, S.; Peng, J.C.; Pereira, F.; M. Pe s; Peshekhonov, D.V.; Platchkov, S.; Pochodzalla, J.; Polyakov, V.A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Riedl, C.; Roskot, M.; Rossiyskaya, N.S.; Ryabchikov, D.I.; Rybnikov, A.; Rychter, A.; Salac, R.; Samoylenko, V.D.; Sandacz, A.; Santos, C.; Sarkar, S.; Savin, I.A.; Sawada, T.; Sbrizzai, G.; Schiavon, P.; Schmidt, K.; Schmieden, H.; Schonning, K.; Schopferer, S.; Seder, E.; Selyunin, A.; Shevchenko, O.Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Smolik, J.; Sozzi, F.; Srnka, A.; Stolarski, M.; Sulc, M.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Tasevsky, M.; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Tosello, F.; Tskhay, V.; Uhl, S.; Veloso, J.; Virius, M.; Vondra, J.; Weisrock, T.; Wilfert, M.; Wolbeek, J. ter; Zaremba, K.; Zavada, P.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.

    2017-01-01

    Using a novel analysis technique, the gluon polarisation in the nucleon is re-evaluated using the longitudinal double-spin asymmetry measured in the cross section of semi-inclusive single-hadron muoproduction with photon virtuality $Q^2>1~({\\rm GeV}/c)^2$. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/$c$ polarised muon beam impinging on a polarised $^6$LiD target. By analysing the full range in hadron transverse momentum $p_T$, the different $p_T$-dependences of the underlying processes are separated using a neural-network approach. In the absence of pQCD calculations at next-to-leading order in the selected kinematic domain, the gluon polarisation $\\Delta g/g$ is evaluated at leading order in pQCD at a hard scale of $\\mu^2 = \\langle Q^2\\rangle = 3(GeV=c)^2$. It is determined in three intervals of the nucleon momentum fraction carried by gluons, $x_g$, covering the range $0.04 \\!<\\! x_{ \\rm g}\\! <\\! 0.28$ . and does not exhibit a significant dependence on $x_{\\rm g}$. Average...

  14. Orientational Analysis of Dodecanethiol and P-Nitrothiophenol SAMs on Metals with Polarisation - dependent SFG spectroscopy

    International Nuclear Information System (INIS)

    Manea, A.

    2011-01-01

    Polarisation-dependent sum frequency generation (SFG) spectroscopy is used to investigate the orientation of molecules on metallic surfaces. In particular, self-assembled monolayers (SAMs) of dodecanethiol (DDT) and of p-nitro thiophenol (p-NTP), grown on Pt and on Au, have been chosen as models to highlight the ability of combining ppp and ssp polarizations sets (representing the polarisation of the involved beams in the conventional order of SFG, Vis and IR beam) to infer orientational information at metallic interfaces. Indeed, using only the ppp set of data, as it is usually done for metallic surfaces, is not sufficient to determine the full molecular orientation. We show here that simply combining ppp and ssp polarizations enables both the tilt and rotation angles of methyl groups in DDT SAMs to be determined. Moreover, for p-NTP, while the SFG active vibrations detected with the ppp polarisation alone provide no orientational information, however, the combination with ssp spectra enables to retrieve the tilt angle of the p-NTP 1,4 axis. Though orientational information obtained by polarisation-dependent measurements has been extensively used at insulating interfaces, we report here their first application to metallic surfaces. (author)

  15. Multi-scalar geographies of polarisation and peripheralisation: A case study of Czechia

    Czech Academy of Sciences Publication Activity Database

    Šimon, Martin

    2017-01-01

    Roč. 16, č. 37 (2017), s. 125-137 ISSN 1732-4254 R&D Projects: GA ČR GA15-10602S Institutional support: RVO:68378025 Keywords : polarisation * peripheralisation * accessibility Subject RIV: AO - Sociology, Demography OBOR OECD: Sociology http://apcz.umk.pl/czasopisma/index.php/BGSS/article/download/bog-2017-0029/12494

  16. Report on polarised and inelastic cold neutron scattering at the Australian Replacement Research Reactor

    International Nuclear Information System (INIS)

    2004-01-01

    The ANSTO's Instrument Workshop on Polarised and Inelastic Cold Neutron Scattering, was held at Lucas Heights on 27-28 January. 30 participants attended, from 6 Australian Universities, 3 ANSTO Divisions, and 5 overseas countries in Asia, Europe and North America. All participants had the opportunity to give their vision for work in 2005 and beyond. The recommendation was that ANSTO proceed with a monochromator/ shield/ polariser system and appropriate dance floor on a cold guide, in such a way that alternative secondary spectrometers (3-axis, LONGPOL-type, reflectometry) can be installed. If the National Science Council of Taiwan proceeds with its cold 3-axis project, ANSTO should then implement the LONGPOL / polarised-beam reflectometry option. If not, ANSTO should implement the cold 3-axis spectrometer. The workshop came to the following additional conclusions: There was a strong sense that any 3-axis spectrometer should have a multi-analyser/multidetector combination, or at least an upgrade path to this. At this stage, there is no case for 2 cold-neutron triple-axis spectrometers at the RRR. The desired Q-range is 0.02-5 Angstroms -1 ; with an energy transfer range of 20 μeV - 15 meV. The instrument is likely to run unpolarised for 2/3 of the time and polarised for the remainder, and the instrument(s) should be designed to allow easy changeover between polarised and unpolarised operation. We expect roughly equal interest/demand in studying single crystals, powders, surfaces/interfaces and naturally disordered systems. There was a strong sense that the facility should eventually have a cold-neutron time-of-flight spectrometer of the IN5 or IN6 type, with a polarised incident beam option, and designed in such a way that polarisation analysis could be implemented if inexpensive large-area analysers become available. This should be a high priority for the next wave of instruments that ANSTO plans to build after 2005

  17. Spontaneous intracranial hypotension.

    LENUS (Irish Health Repository)

    Fullam, L

    2012-01-31

    INTRODUCTION: Spontaneous\\/primary intracranial hypotension is characterised by orthostatic headache and is associated with characteristic magnetic resonance imaging findings. CASE REPORT: We present a case report of a patient with typical symptoms and classical radiological images. DISCUSSION: Spontaneous intracranial hypotension is an under-recognised cause of headache and can be diagnosed by history of typical orthostatic headache and findings on MRI brain.

  18. Leading-order determination of the gluon polarisation from semi-inclusive deep inelastic scattering data

    International Nuclear Information System (INIS)

    Adolph, C.; Braun, C.; Eyrich, W.; Lehmann, A.; Zink, A.; Aghasyan, M.; Birsa, R.; Dalla Torre, S.; Levorato, S.; Santos, C.; Sozzi, F.; Tessaro, S.; Tessarotto, F.; Akhunzyanov, R.; Alexeev, G.D.; Anfimov, N.V.; Anosov, V.; Efremov, A.; Gavrichtchouk, O.P.; Guskov, A.; Ivanshin, Yu.; Kisselev, Yu.; Kouznetsov, O.M.; Kroumchtein, Z.V.; Meshcheryakov, G.V.; Nagaytsev, A.; Olshevsky, A.G.; Orlov, I.; Peshekhonov, D.V.; Rossiyskaya, N.S.; Rybnikov, A.; Savin, I.A.; Selyunin, A.; Shevchenko, O.Yu.; Slunecka, M.; Smolik, J.; Tasevsky, M.; Zavada, P.; Zemlyanichkina, E.; Alexeev, M.G.; Amoroso, A.; Balestra, F.; Chiosso, M.; Gnesi, I.; Grasso, A.; Ivanov, A.; Kotzinian, A.M.; Longo, R.; Parsamyan, B.; Takekawa, S.; Andrieux, V.; Boer, M.; Curiel, Q.; Ferrero, A.; Fuchey, E.; Hose, N. d'; Kunne, F.; Levillain, M.; Magnon, A.; Marchand, C.; Neyret, D.; Platchkov, S.; Seder, E.; Thibaud, F.; Augustyniak, W.; Klimaszewski, K.; Kurek, K.; Marianski, B.; Sandacz, A.; Szabelski, A.; Sznajder, P.; Austregesilo, A.; Chung, S.U.; Friedrich, J.M.; Grabmueller, S.; Grube, B.; Haas, F.; Huber, S.; Kraemer, M.; Krinner, F.; Paul, S.; Uhl, S.; Azevedo, C.D.R.; Pereira, F.; Veloso, J.; Badelek, B.; Barth, J.; Hahne, D.; Klein, F.; Pretz, J.; Schmieden, H.; Beck, R.; Bisplinghoff, J.; Eversheim, P.D.; Hinterberger, F.; Jahn, R.; Joosten, R.; Ketzer, B.; Mikhasenko, M.; Bedfer, Y.; Bernhard, J.; Bicker, K.; Bielert, E.R.; Mallot, G.K.; Schoenning, K.; Bodlak, M.; Finger, M.; Finger, M. Jr.; Matousek, J.; Pesek, M.; Roskot, M.; Bordalo, P.; Franco, C.; Nunes, A.S.; Quaresma, M.; Quintans, C.; Ramos, S.; Silva, L.; Stolarski, M.; Bradamante, F.; Bressan, A.; Dasgupta, S.; Makke, N.; Martin, A.; Sbrizzai, G.; Schiavon, P.; Buechele, M.; Fischer, H.; Gorzellik, M.; Grussenmeyer, T.; Heinsius, F.H.; Herrmann, F.; Joerg, P.; Koenigsmann, K.; Kremser, P.; Nowak, W.D.; Regali, C.; Schmidt, K.; Schopferer, S.; Sirtl, S.; Szameitat, T.; Wolbeek, J. ter; Chang, W.C.; Hsieh, C.Y.; Sawada, T.; Choi, I.; Giordano, F.; Grosse Perdekamp, M.; Heitz, R.; Kulinich, Y.; Makins, N.; Montuenga, P.; Peng, J.C.; Riedl, C.; Cicuttin, A.; Crespo, M.L.; Dasgupta, S.S.; Dhara, L.; Sarkar, S.; Sinha, L.; Denisov, O.Yu.; Maggiora, A.; Panzieri, D.; Tosello, F.; Donskov, S.V.; Khaustov, G.V.; Khokhlov, Yu.A.; Kolosov, V.N.; Konstantinov, V.F.; Lednev, A.A.; Mikhailov, Yu.V.; Nikolaenko, V.I.; Polyakov, V.A.; Ryabchikov, D.I.; Samoylenko, V.D.; Doshita, N.; Hashimoto, R.; Ishimoto, S.; Iwata, T.; Kondo, K.; Matsuda, H.; Michigami, T.; Miyachi, Y.; Nukazuka, G.; Suzuki, H.; Duic, V.; Dziewiecki, M.; Kurjata, R.P.; Marzec, J.; Rychter, A.; Zaremba, K.; Ziembicki, M.; Fresne von Hohenesche, N. du; Harrach, D. von; Kabuss, E.; Nerling, F.; Ostrick, M.; Pochodzalla, J.; Weisrock, T.; Wilfert, M.

    2017-01-01

    Using a novel analysis technique, the gluon polarisation in the nucleon is re-evaluated using the longitudinal double-spin asymmetry measured in the cross section of semi-inclusive single-hadron muoproduction with photon virtuality Q"2 > 1 (GeV/c)"2. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/c polarised muon beam impinging on a polarised "6LiD target. By analysing the full range in hadron transverse momentum p_T, the different p_T-dependences of the underlying processes are separated using a neural-network approach. In the absence of pQCD calculations at next-to-leading order in the selected kinematic domain, the gluon polarisation Δg/g is evaluated at leading order in pQCD at a hard scale of μ"2 = left angle Q"2 right angle = 3 (GeV/c)"2. It is determined in three intervals of the nucleon momentum fraction carried by gluons, x_g, covering the range 0.04 < x_g < 0.28 and does not exhibit a significant dependence on x_g. The average over the three intervals, left angle Δg/g right angle = 0.113 ± 0.038_(_s_t_a_t_._) ± 0.036_(_s_y_s_t_._) at left angle x_g right angle ∼ 0.10, suggests that the gluon polarisation is positive in the measured x_g range. (orig.)

  19. Leading-order determination of the gluon polarisation from semi-inclusive deep inelastic scattering data

    Energy Technology Data Exchange (ETDEWEB)

    Adolph, C.; Braun, C.; Eyrich, W.; Lehmann, A.; Zink, A. [Universitaet Erlangen-Nuernberg, Physikalisches Institut, Erlangen (Germany); Aghasyan, M.; Birsa, R.; Dalla Torre, S.; Levorato, S.; Santos, C.; Sozzi, F.; Tessaro, S.; Tessarotto, F. [INFN, Trieste (Italy); Akhunzyanov, R.; Alexeev, G.D.; Anfimov, N.V.; Anosov, V.; Efremov, A.; Gavrichtchouk, O.P.; Guskov, A.; Ivanshin, Yu.; Kisselev, Yu.; Kouznetsov, O.M.; Kroumchtein, Z.V.; Meshcheryakov, G.V.; Nagaytsev, A.; Olshevsky, A.G.; Orlov, I.; Peshekhonov, D.V.; Rossiyskaya, N.S.; Rybnikov, A.; Savin, I.A.; Selyunin, A.; Shevchenko, O.Yu.; Slunecka, M.; Smolik, J.; Tasevsky, M.; Zavada, P.; Zemlyanichkina, E. [Joint Institute for Nuclear Research, Dubna, Moscow region (Russian Federation); Alexeev, M.G. [University of Turin, Department of Physics, Turin (Italy); Amoroso, A.; Balestra, F.; Chiosso, M.; Gnesi, I.; Grasso, A.; Ivanov, A.; Kotzinian, A.M.; Longo, R.; Parsamyan, B.; Takekawa, S. [University of Turin, Department of Physics, Turin (Italy); INFN, Turin (Italy); Andrieux, V.; Boer, M.; Curiel, Q.; Ferrero, A.; Fuchey, E.; Hose, N. d' ; Kunne, F.; Levillain, M.; Magnon, A.; Marchand, C.; Neyret, D.; Platchkov, S.; Seder, E.; Thibaud, F. [CEA IRFU/SPhN Saclay, Gif-sur-Yvette (France); Augustyniak, W.; Klimaszewski, K.; Kurek, K.; Marianski, B.; Sandacz, A.; Szabelski, A.; Sznajder, P. [National Centre for Nuclear Research, Warsaw (Poland); Austregesilo, A.; Chung, S.U.; Friedrich, J.M.; Grabmueller, S.; Grube, B.; Haas, F.; Huber, S.; Kraemer, M.; Krinner, F.; Paul, S.; Uhl, S. [Technische Universitaet Muenchen, Physik Department, Garching (Germany); Azevedo, C.D.R.; Pereira, F.; Veloso, J. [University of Aveiro, Department of Physics, Aveiro (Portugal); Badelek, B. [University of Warsaw, Faculty of Physics, Warsaw (Poland); Barth, J.; Hahne, D.; Klein, F.; Pretz, J.; Schmieden, H. [Universitaet Bonn, Physikalisches Institut, Bonn (Germany); Beck, R.; Bisplinghoff, J.; Eversheim, P.D.; Hinterberger, F.; Jahn, R.; Joosten, R.; Ketzer, B.; Mikhasenko, M. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik, Bonn (Germany); Bedfer, Y. [CERN, Geneva 23 (Switzerland); CEA IRFU/SPhN Saclay, Gif-sur-Yvette (France); Bernhard, J. [CERN, Geneva 23 (Switzerland); Universitaet Mainz, Institut fuer Kernphysik, Mainz (Germany); Bicker, K. [CERN, Geneva 23 (Switzerland); Technische Universitaet Muenchen, Physik Department, Garching (Germany); Bielert, E.R.; Mallot, G.K.; Schoenning, K. [CERN, Geneva 23 (Switzerland); Bodlak, M.; Finger, M.; Finger, M. Jr.; Matousek, J.; Pesek, M.; Roskot, M. [Charles University in Prague, Faculty of Mathematics and Physics, Prague (Czech Republic); Bordalo, P.; Franco, C.; Nunes, A.S.; Quaresma, M.; Quintans, C.; Ramos, S.; Silva, L.; Stolarski, M. [LIP, Lisbon (Portugal); Bradamante, F.; Bressan, A.; Dasgupta, S.; Makke, N.; Martin, A.; Sbrizzai, G.; Schiavon, P. [University of Trieste, Department of Physics, Trieste (Italy); INFN, Trieste (Italy); Buechele, M.; Fischer, H.; Gorzellik, M.; Grussenmeyer, T.; Heinsius, F.H.; Herrmann, F.; Joerg, P.; Koenigsmann, K.; Kremser, P.; Nowak, W.D.; Regali, C.; Schmidt, K.; Schopferer, S.; Sirtl, S.; Szameitat, T.; Wolbeek, J. ter [Universitaet Freiburg, Physikalisches Institut, Freiburg (Germany); Chang, W.C.; Hsieh, C.Y.; Sawada, T. [Academia Sinica, Institute of Physics, Taipei (China); Choi, I.; Giordano, F.; Grosse Perdekamp, M.; Heitz, R.; Kulinich, Y.; Makins, N.; Montuenga, P.; Peng, J.C.; Riedl, C. [University of Illinois at Urbana-Champaign, Department of Physics, Urbana, IL (United States); Cicuttin, A.; Crespo, M.L. [INFN, Trieste (Italy); Abdus Salam ICTP, Trieste (Italy); Dasgupta, S.S.; Dhara, L.; Sarkar, S.; Sinha, L. [Matrivani Institute of Experimental Research and Education, Calcutta (India); Denisov, O.Yu.; Maggiora, A.; Panzieri, D.; Tosello, F. [INFN, Turin (Italy); Donskov, S.V.; Khaustov, G.V.; Khokhlov, Yu.A.; Kolosov, V.N.; Konstantinov, V.F.; Lednev, A.A.; Mikhailov, Yu.V.; Nikolaenko, V.I.; Polyakov, V.A.; Ryabchikov, D.I.; Samoylenko, V.D. [State Scientific Center Institute for High Energy Physics of National Research Center ' Kurchatov Institute' , Protvino (Russian Federation); Doshita, N.; Hashimoto, R.; Ishimoto, S.; Iwata, T.; Kondo, K.; Matsuda, H.; Michigami, T.; Miyachi, Y.; Nukazuka, G.; Suzuki, H. [Yamagata University, Yamagata (Japan); Duic, V. [University of Trieste, Department of Physics, Trieste (Italy); Dziewiecki, M.; Kurjata, R.P.; Marzec, J.; Rychter, A.; Zaremba, K.; Ziembicki, M. [Warsaw University of Technology, Institute of Radioelectronics, Warsaw (Poland); Fresne von Hohenesche, N. du; Harrach, D. von; Kabuss, E.; Nerling, F.; Ostrick, M.; Pochodzalla, J.; Weisrock, T.; Wilfert, M. [Universitaet Mainz, Institut fuer Kernphysik, Mainz (Germany); Collaboration: COMPASS Collaboration; and others

    2017-04-15

    Using a novel analysis technique, the gluon polarisation in the nucleon is re-evaluated using the longitudinal double-spin asymmetry measured in the cross section of semi-inclusive single-hadron muoproduction with photon virtuality Q{sup 2} > 1 (GeV/c){sup 2}. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/c polarised muon beam impinging on a polarised {sup 6}LiD target. By analysing the full range in hadron transverse momentum p{sub T}, the different p{sub T}-dependences of the underlying processes are separated using a neural-network approach. In the absence of pQCD calculations at next-to-leading order in the selected kinematic domain, the gluon polarisation Δg/g is evaluated at leading order in pQCD at a hard scale of μ{sup 2} = left angle Q{sup 2} right angle = 3 (GeV/c){sup 2}. It is determined in three intervals of the nucleon momentum fraction carried by gluons, x{sub g}, covering the range 0.04 < x{sub g} < 0.28 and does not exhibit a significant dependence on x{sub g}. The average over the three intervals, left angle Δg/g right angle = 0.113 ± 0.038{sub (stat.)} ± 0.036{sub (syst.)} at left angle x{sub g} right angle ∼ 0.10, suggests that the gluon polarisation is positive in the measured x{sub g} range. (orig.)

  20. Spontaneous Scalarization: Dead or Alive?

    Science.gov (United States)

    Berti, Emanuele; Crispino, Luis; Gerosa, Davide; Gualtieri, Leonardo; Horbatsch, Michael; Macedo, Caio; Okada da Silva, Hector; Pani, Paolo; Sotani, Hajime; Sperhake, Ulrich

    2015-04-01

    In 1993, Damour and Esposito-Farese showed that a wide class of scalar-tensor theories can pass weak-field gravitational tests and exhibit nonperturbative strong-field deviations away from General Relativity in systems involving neutron stars. These deviations are possible in the presence of ``spontaneous scalarization,'' a phase transition similar in nature to spontaneous magnetization in ferromagnets. More than twenty years after the original proposal, binary pulsar experiments have severely constrained the possibility of spontaneous scalarization occurring in nature. I will show that these experimental constraints have important implications for the torsional oscillation frequencies of neutron stars and for the so-called ``I-Love-Q'' relations in scalar-tensor theories. I will also argue that there is still hope to observe strong scalarization effects, despite the strong experimental bounds on the original mechanism. In particular, I will discuss two mechanisms that could produce strong scalarization in neutron stars: anisotropy and multiscalarization. This work was supported by NSF CAREER Award PHY-1055103.

  1. Contiguous polarisation spectra of the Earth from 300-850 nm measured by GOME-2 onboard MetOp-A

    Science.gov (United States)

    Tilstra, L. G.; Lang, R.; Munro, R.; Aben, I.; Stammes, P.

    2013-12-01

    In this paper we present the first contiguous high-resolution spectra of the Earth's polarisation observed by a satellite instrument. The measurements of the Stokes fraction Q/I are performed by the spectrometer GOME-2 onboard the MetOp-A satellite. Polarisation measurements by GOME-2 are performed by onboard polarisation measurement devices (PMDs) and the high-resolution measurements discussed in this paper are taken in the special "PMD RAW" mode of operation. The spectral resolution of these PMD RAW polarisation measurements varies from 3 nm in the ultraviolet (UV) to 35 nm in the near-infrared wavelength range. We first compare measurements of the polarisation from cloud-free scenes with radiative transfer calculations for a number of cases. We find good agreement but also a spectral discrepancy at 800 nm, which we attribute to remaining imperfections in the calibration key data. Secondly, we study the polarisation of scenes with special scattering geometries that normally lead to near-zero Q/I. The GOME-2 polarisation spectra indeed show this behaviour and confirm the existence of the small discrepancy found earlier. Thirdly, we study the Earth polarisation for a variety of scenes. This provides a blueprint of Q/I over land and sea surfaces for various degrees of cloud cover. Fourthly, we compare the spectral dependence of measurements of Q/I in the UV with the generalised distribution function that was proposed in the past (Schutgens and Stammes, 2002) to describe the shape of the UV polarisation spectrum. The GOME-2 data confirm that these functions match the spectral behaviour captured by the GOME-2 PMD RAW mode.

  2. Contiguous polarisation spectra of the Earth from 300 to 850 nm measured by GOME-2 onboard MetOp-A

    Science.gov (United States)

    Tilstra, L. G.; Lang, R.; Munro, R.; Aben, I.; Stammes, P.

    2014-07-01

    In this paper we present the first contiguous high-resolution spectra of the Earth's polarisation observed by a satellite instrument. The measurements of the Stokes fraction Q/I are performed by the spectrometer GOME-2 onboard the MetOp-A satellite. Polarisation measurements by GOME-2 are performed by onboard polarisation measurement devices (PMDs) and the high-resolution measurements discussed in this paper are taken in the special "PMD RAW" mode of operation. The spectral resolution of these PMD RAW polarisation measurements varies from 3 nm in the ultraviolet (UV) to 35 nm in the near-infrared wavelength range. We first compare measurements of the polarisation from cloud-free scenes with radiative transfer calculations for a number of cases. We find good agreement but also a spectral discrepancy at 800 nm, which we attribute to remaining imperfections in the calibration key data. Secondly, we study the polarisation of scenes with special scattering geometries that normally lead to near-zero Q/I. The GOME-2 polarisation spectra indeed show this behaviour and confirm the existence of the small discrepancy found earlier. Thirdly, we study the Earth polarisation for a variety of scenes. This provides a blueprint of Q/I over land and sea surfaces for various degrees of cloud cover. Fourthly, we compare the spectral dependence of measurements of Q/I in the UV with the generalised distribution function proposed by Schutgens and Stammes (2002) to describe the shape of the UV polarisation spectrum. The GOME-2 data confirm that these functions match the spectral behaviour captured by the GOME-2 PMD RAW mode.

  3. Measurement of $\\psi(2S)$ polarisation in $pp$ collisions at $\\sqrt{s}=7$ TeV

    CERN Document Server

    Aaij, Roel; Adinolfi, Marco; Affolder, Anthony; Ajaltouni, Ziad; Albrecht, Johannes; Alessio, Federico; Alexander, Michael; Ali, Suvayu; Alkhazov, Georgy; Alvarez Cartelle, Paula; Alves Jr, Antonio; Amato, Sandra; Amerio, Silvia; Amhis, Yasmine; An, Liupan; Anderlini, Lucio; Anderson, Jonathan; Andreassen, Rolf; Andreotti, Mirco; Andrews, Jason; Appleby, Robert; Aquines Gutierrez, Osvaldo; Archilli, Flavio; Artamonov, Alexander; Artuso, Marina; Aslanides, Elie; Auriemma, Giulio; Baalouch, Marouen; Bachmann, Sebastian; Back, John; Badalov, Alexey; Balagura, Vladislav; Baldini, Wander; Barlow, Roger; Barschel, Colin; Barsuk, Sergey; Barter, William; Batozskaya, Varvara; Bauer, Thomas; Bay, Aurelio; Beddow, John; Bedeschi, Franco; Bediaga, Ignacio; Belogurov, Sergey; Belous, Konstantin; Belyaev, Ivan; Ben-Haim, Eli; Bencivenni, Giovanni; Benson, Sean; Benton, Jack; Berezhnoy, Alexander; Bernet, Roland; Bettler, Marc-Olivier; van Beuzekom, Martinus; Bien, Alexander; Bifani, Simone; Bird, Thomas; Bizzeti, Andrea; Bjørnstad, Pål Marius; Blake, Thomas; Blanc, Frédéric; Blouw, Johan; Blusk, Steven; Bocci, Valerio; Bondar, Alexander; Bondar, Nikolay; Bonivento, Walter; Borghi, Silvia; Borgia, Alessandra; Borsato, Martino; Bowcock, Themistocles; Bowen, Espen Eie; Bozzi, Concezio; Brambach, Tobias; van den Brand, Johannes; Bressieux, Joël; Brett, David; Britsch, Markward; Britton, Thomas; Brook, Nicholas; Brown, Henry; Bursche, Albert; Busetto, Giovanni; Buytaert, Jan; Cadeddu, Sandro; Calabrese, Roberto; Callot, Olivier; Calvi, Marta; Calvo Gomez, Miriam; Camboni, Alessandro; Campana, Pierluigi; Campora Perez, Daniel; Carbone, Angelo; Carboni, Giovanni; Cardinale, Roberta; Cardini, Alessandro; Carranza-Mejia, Hector; Carson, Laurence; Carvalho Akiba, Kazuyoshi; Casse, Gianluigi; Cassina, Lorenzo; Castillo Garcia, Lucia; Cattaneo, Marco; Cauet, Christophe; Cenci, Riccardo; Charles, Matthew; Charpentier, Philippe; Cheung, Shu-Faye; Chiapolini, Nicola; Chrzaszcz, Marcin; Ciba, Krzystof; Cid Vidal, Xabier; Ciezarek, Gregory; Clarke, Peter; Clemencic, Marco; Cliff, Harry; Closier, Joel; Coca, Cornelia; Coco, Victor; Cogan, Julien; Cogneras, Eric; Collins, Paula; Comerma-Montells, Albert; Contu, Andrea; Cook, Andrew; Coombes, Matthew; Coquereau, Samuel; Corti, Gloria; Corvo, Marco; Counts, Ian; Couturier, Benjamin; Cowan, Greig; Craik, Daniel Charles; Cruz Torres, Melissa Maria; Cunliffe, Samuel; Currie, Robert; D'Ambrosio, Carmelo; Dalseno, Jeremy; David, Pascal; David, Pieter; Davis, Adam; De Bruyn, Kristof; De Capua, Stefano; De Cian, Michel; De Miranda, Jussara; De Paula, Leandro; De Silva, Weeraddana; De Simone, Patrizia; Decamp, Daniel; Deckenhoff, Mirko; Del Buono, Luigi; Déléage, Nicolas; Derkach, Denis; Deschamps, Olivier; Dettori, Francesco; Di Canto, Angelo; Dijkstra, Hans; Donleavy, Stephanie; Dordei, Francesca; Dorigo, Mirco; Dosil Suárez, Alvaro; Dossett, David; Dovbnya, Anatoliy; Dupertuis, Frederic; Durante, Paolo; Dzhelyadin, Rustem; Dziurda, Agnieszka; Dzyuba, Alexey; Easo, Sajan; Egede, Ulrik; Egorychev, Victor; Eidelman, Semen; Eisenhardt, Stephan; Eitschberger, Ulrich; Ekelhof, Robert; Eklund, Lars; El Rifai, Ibrahim; Elsasser, Christian; Esen, Sevda; Evans, Timothy; Falabella, Antonio; Färber, Christian; Farinelli, Chiara; Farry, Stephen; Ferguson, Dianne; Fernandez Albor, Victor; Ferreira Rodrigues, Fernando; Ferro-Luzzi, Massimiliano; Filippov, Sergey; Fiore, Marco; Fiorini, Massimiliano; Firlej, Miroslaw; Fitzpatrick, Conor; Fiutowski, Tomasz; Fontana, Marianna; Fontanelli, Flavio; Forty, Roger; Francisco, Oscar; Frank, Markus; Frei, Christoph; Frosini, Maddalena; Fu, Jinlin; Furfaro, Emiliano; Gallas Torreira, Abraham; Galli, Domenico; Gandelman, Miriam; Gandini, Paolo; Gao, Yuanning; Garofoli, Justin; Garra Tico, Jordi; Garrido, Lluis; Gaspar, Clara; Gauld, Rhorry; Gavardi, Laura; Gersabeck, Evelina; Gersabeck, Marco; Gershon, Timothy; Ghez, Philippe; Gianelle, Alessio; Giani', Sebastiana; Gibson, Valerie; Giubega, Lavinia-Helena; Gligorov, Vladimir; Göbel, Carla; Golubkov, Dmitry; Golutvin, Andrey; Gomes, Alvaro; Gordon, Hamish; Gotti, Claudio; Grabalosa Gándara, Marc; Graciani Diaz, Ricardo; Granado Cardoso, Luis Alberto; Graugés, Eugeni; Graziani, Giacomo; Grecu, Alexandru; Greening, Edward; Gregson, Sam; Griffith, Peter; Grillo, Lucia; Grünberg, Oliver; Gui, Bin; Gushchin, Evgeny; Guz, Yury; Gys, Thierry; Hadjivasiliou, Christos; Haefeli, Guido; Haen, Christophe; Haines, Susan; Hall, Samuel; Hamilton, Brian; Hampson, Thomas; Han, Xiaoxue; Hansmann-Menzemer, Stephanie; Harnew, Neville; Harnew, Samuel; Harrison, Jonathan; Hartmann, Thomas; He, Jibo; Head, Timothy; Heijne, Veerle; Hennessy, Karol; Henrard, Pierre; Henry, Louis; Hernando Morata, Jose Angel; van Herwijnen, Eric; Heß, Miriam; Hicheur, Adlène; Hill, Donal; Hoballah, Mostafa; Hombach, Christoph; Hulsbergen, Wouter; Hunt, Philip; Hussain, Nazim; Hutchcroft, David; Hynds, Daniel; Iakovenko, Viktor; Idzik, Marek; Ilten, Philip; Jacobsson, Richard; Jaeger, Andreas; Jalocha, Pawel; Jans, Eddy; Jaton, Pierre; Jawahery, Abolhassan; Jezabek, Marek; Jing, Fanfan; John, Malcolm; Johnson, Daniel; Jones, Christopher; Joram, Christian; Jost, Beat; Jurik, Nathan; Kaballo, Michael; Kandybei, Sergii; Kanso, Walaa; Karacson, Matthias; Karbach, Moritz; Kelsey, Matthew; Kenyon, Ian; Ketel, Tjeerd; Khanji, Basem; Khurewathanakul, Chitsanu; Klaver, Suzanne; Kochebina, Olga; Kolpin, Michael; Komarov, Ilya; Koopman, Rose; Koppenburg, Patrick; Korolev, Mikhail; Kozlinskiy, Alexandr; Kravchuk, Leonid; Kreplin, Katharina; Kreps, Michal; Krocker, Georg; Krokovny, Pavel; Kruse, Florian; Kucharczyk, Marcin; Kudryavtsev, Vasily; Kurek, Krzysztof; Kvaratskheliya, Tengiz; La Thi, Viet Nga; Lacarrere, Daniel; Lafferty, George; Lai, Adriano; Lambert, Dean; Lambert, Robert W; Lanciotti, Elisa; Lanfranchi, Gaia; Langenbruch, Christoph; Latham, Thomas; Lazzeroni, Cristina; Le Gac, Renaud; van Leerdam, Jeroen; Lees, Jean-Pierre; Lefèvre, Regis; Leflat, Alexander; Lefrançois, Jacques; Leo, Sabato; Leroy, Olivier; Lesiak, Tadeusz; Leverington, Blake; Li, Yiming; Liles, Myfanwy; Lindner, Rolf; Linn, Christian; Lionetto, Federica; Liu, Bo; Liu, Guoming; Lohn, Stefan; Longstaff, Iain; Longstaff, Ian; Lopes, Jose; Lopez-March, Neus; Lowdon, Peter; Lu, Haiting; Lucchesi, Donatella; Luisier, Johan; Luo, Haofei; Lupato, Anna; Luppi, Eleonora; Lupton, Oliver; Machefert, Frederic; Machikhiliyan, Irina V; Maciuc, Florin; Maev, Oleg; Malde, Sneha; Manca, Giulia; Mancinelli, Giampiero; Manzali, Matteo; Maratas, Jan; Marchand, Jean François; Marconi, Umberto; Marino, Pietro; Märki, Raphael; Marks, Jörg; Martellotti, Giuseppe; Martens, Aurelien; Martín Sánchez, Alexandra; Martinelli, Maurizio; Martinez Santos, Diego; Martinez Vidal, Fernando; Martins Tostes, Danielle; Massafferri, André; Matev, Rosen; Mathe, Zoltan; Matteuzzi, Clara; Mazurov, Alexander; McCann, Michael; McCarthy, James; McNab, Andrew; McNulty, Ronan; McSkelly, Ben; Meadows, Brian; Meier, Frank; Meissner, Marco; Merk, Marcel; Milanes, Diego Alejandro; Minard, Marie-Noelle; Molina Rodriguez, Josue; Monteil, Stephane; Moran, Dermot; Morandin, Mauro; Morawski, Piotr; Mordà, Alessandro; Morello, Michael Joseph; Moron, Jakub; Mountain, Raymond; Muheim, Franz; Müller, Katharina; Muresan, Raluca; Muster, Bastien; Naik, Paras; Nakada, Tatsuya; Nandakumar, Raja; Nasteva, Irina; Needham, Matthew; Neri, Nicola; Neubert, Sebastian; Neufeld, Niko; Neuner, Max; Nguyen, Anh Duc; Nguyen, Thi-Dung; Nguyen-Mau, Chung; Nicol, Michelle; Niess, Valentin; Niet, Ramon; Nikitin, Nikolay; Nikodem, Thomas; Novoselov, Alexey; Oblakowska-Mucha, Agnieszka; Obraztsov, Vladimir; Oggero, Serena; Ogilvy, Stephen; Okhrimenko, Oleksandr; Oldeman, Rudolf; Onderwater, Gerco; Orlandea, Marius; Otalora Goicochea, Juan Martin; Owen, Patrick; Oyanguren, Maria Arantza; Pal, Bilas Kanti; Palano, Antimo; Palombo, Fernando; Palutan, Matteo; Panman, Jacob; Papanestis, Antonios; Pappagallo, Marco; Parkes, Christopher; Parkinson, Christopher John; Passaleva, Giovanni; Patel, Girish; Patel, Mitesh; Patrignani, Claudia; Pazos Alvarez, Antonio; Pearce, Alex; Pellegrino, Antonio; Penso, Gianni; Pepe Altarelli, Monica; Perazzini, Stefano; Perez Trigo, Eliseo; Perret, Pascal; Perrin-Terrin, Mathieu; Pescatore, Luca; Pesen, Erhan; Petridis, Konstantin; Petrolini, Alessandro; Picatoste Olloqui, Eduardo; Pietrzyk, Boleslaw; Pilař, Tomas; Pinci, Davide; Pistone, Alessandro; Playfer, Stephen; Plo Casasus, Maximo; Polci, Francesco; Polok, Grzegorz; Poluektov, Anton; Polycarpo, Erica; Popov, Alexander; Popov, Dmitry; Popovici, Bogdan; Potterat, Cédric; Powell, Andrew; Prisciandaro, Jessica; Pritchard, Adrian; Prouve, Claire; Pugatch, Valery; Puig Navarro, Albert; Punzi, Giovanni; Qian, Wenbin; Rachwal, Bartolomiej; Rademacker, Jonas; Rakotomiaramanana, Barinjaka; Rama, Matteo; Rangel, Murilo; Raniuk, Iurii; Rauschmayr, Nathalie; Raven, Gerhard; Redford, Sophie; Reichert, Stefanie; Reid, Matthew; dos Reis, Alberto; Ricciardi, Stefania; Richards, Alexander; Rinnert, Kurt; Rives Molina, Vincente; Roa Romero, Diego; Robbe, Patrick; Rodrigues, Ana Barbara; Rodrigues, Eduardo; Rodriguez Perez, Pablo; Roiser, Stefan; Romanovsky, Vladimir; Romero Vidal, Antonio; Rotondo, Marcello; Rouvinet, Julien; Ruf, Thomas; Ruffini, Fabrizio; Ruiz, Hugo; Ruiz Valls, Pablo; Sabatino, Giovanni; Saborido Silva, Juan Jose; Sagidova, Naylya; Sail, Paul; Saitta, Biagio; Salustino Guimaraes, Valdir; Sanchez Mayordomo, Carlos; Sanmartin Sedes, Brais; Santacesaria, Roberta; Santamarina Rios, Cibran; Santovetti, Emanuele; Sapunov, Matvey; Sarti, Alessio; Satriano, Celestina; Satta, Alessia; Savrie, Mauro; Savrina, Darya; Schiller, Manuel; Schindler, Heinrich; Schlupp, Maximilian; Schmelling, Michael; Schmidt, Burkhard; Schneider, Olivier; Schopper, Andreas; Schune, Marie Helene; Schwemmer, Rainer; Sciascia, Barbara; Sciubba, Adalberto; Seco, Marcos; Semennikov, Alexander; Senderowska, Katarzyna; Sepp, Indrek; Serra, Nicola; Serrano, Justine; Sestini, Lorenzo; Seyfert, Paul; Shapkin, Mikhail; Shapoval, Illya; Shcheglov, Yury; Shears, Tara; Shekhtman, Lev; Shevchenko, Vladimir; Shires, Alexander; Silva Coutinho, Rafael; Simi, Gabriele; Sirendi, Marek; Skidmore, Nicola; Skwarnicki, Tomasz; Smith, Anthony; Smith, Edmund; Smith, Eluned; Smith, Jackson; Smith, Mark; Snoek, Hella; Sokoloff, Michael; Soler, Paul; Soomro, Fatima; Souza, Daniel; Souza De Paula, Bruno; Spaan, Bernhard; Sparkes, Ailsa; Spinella, Franco; Spradlin, Patrick; Stagni, Federico; Stahl, Sascha; Steinkamp, Olaf; Stenyakin, Oleg; Stevenson, Scott; Stoica, Sabin; Stone, Sheldon; Storaci, Barbara; Stracka, Simone; Straticiuc, Mihai; Straumann, Ulrich; Stroili, Roberto; Subbiah, Vijay Kartik; Sun, Liang; Sutcliffe, William; Swientek, Krzysztof; Swientek, Stefan; Syropoulos, Vasileios; Szczekowski, Marek; Szczypka, Paul; Szilard, Daniela; Szumlak, Tomasz; T'Jampens, Stephane; Teklishyn, Maksym; Tellarini, Giulia; Teodorescu, Eliza; Teubert, Frederic; Thomas, Christopher; Thomas, Eric; van Tilburg, Jeroen; Tisserand, Vincent; Tobin, Mark; Tolk, Siim; Tomassetti, Luca; Tonelli, Diego; Topp-Joergensen, Stig; Torr, Nicholas; Tournefier, Edwige; Tourneur, Stephane; Tran, Minh Tâm; Tresch, Marco; Tsaregorodtsev, Andrei; Tsopelas, Panagiotis; Tuning, Niels; Ubeda Garcia, Mario; Ukleja, Artur; Ustyuzhanin, Andrey; Uwer, Ulrich; Vagnoni, Vincenzo; Valenti, Giovanni; Vallier, Alexis; Vazquez Gomez, Ricardo; Vazquez Regueiro, Pablo; Vázquez Sierra, Carlos; Vecchi, Stefania; Velthuis, Jaap; Veltri, Michele; Veneziano, Giovanni; Vesterinen, Mika; Viaud, Benoit; Vieira, Daniel; Vieites Diaz, Maria; Vilasis-Cardona, Xavier; Vollhardt, Achim; Volyanskyy, Dmytro; Voong, David; Vorobyev, Alexey; Vorobyev, Vitaly; Voß, Christian; Voss, Helge; de Vries, Jacco; Waldi, Roland; Wallace, Charlotte; Wallace, Ronan; Walsh, John; Wandernoth, Sebastian; Wang, Jianchun; Ward, David; Watson, Nigel; Webber, Adam Dane; Websdale, David; Whitehead, Mark; Wicht, Jean; Wiedner, Dirk; Wiggers, Leo; Wilkinson, Guy; Williams, Matthew; Williams, Mike; Wilson, Fergus; Wimberley, Jack; Wishahi, Julian; Wislicki, Wojciech; Witek, Mariusz; Wormser, Guy; Wotton, Stephen; Wright, Simon; Wu, Suzhi; Wyllie, Kenneth; Xie, Yuehong; Xing, Zhou; Xu, Zhirui; Yang, Zhenwei; Yuan, Xuhao; Yushchenko, Oleg; Zangoli, Maria; Zavertyaev, Mikhail; Zhang, Feng; Zhang, Liming; Zhang, Wen Chao; Zhang, Yanxi; Zhelezov, Alexey; Zhokhov, Anatoly; Zhong, Liang; Zvyagin, Alexander

    2014-01-01

    The polarisation of prompt $\\psi(2S)$ mesons is measured by performing an angular analysis of $\\psi(2S)\\rightarrow \\mu^{+} \\mu^{-}$ decays using proton-proton collision data, corresponding to an integrated luminosity of 1.0 fb$^{-1}$, collected by the LHCb detector at a centre-of-mass energy of 7 TeV. The polarisation is measured in bins of transverse momentum $p_\\mathrm{T}$ and rapidity $y$ in the kinematic region $3.5polarisation is observed.

  4. Measurement of [Formula: see text] polarisation in [Formula: see text] collisions at [Formula: see text] = 7 TeV.

    Science.gov (United States)

    Aaij, R; Adeva, B; Adinolfi, M; Affolder, A; Ajaltouni, Z; 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; Andreassen, R; Andreotti, M; Andrews, J E; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Bachmann, S; Back, J J; Badalov, A; Balagura, V; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Batozskaya, V; Bauer, Th; Bay, A; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Borsato, M; Bowcock, T J V; Bowen, E; Bozzi, C; Brambach, T; van den Brand, J; Bressieux, J; Brett, D; Britsch, M; Britton, T; Brook, N H; Brown, H; Bursche, A; Busetto, G; Buytaert, J; Cadeddu, S; Calabrese, R; Callot, O; Calvi, M; Calvo Gomez, M; Camboni, A; Campana, P; Campora Perez, D; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carranza-Mejia, H; Carson, L; Carvalho Akiba, K; Casse, G; Cassina, L; Castillo Garcia, L; Cattaneo, M; Cauet, Ch; Cenci, R; Charles, M; Charpentier, Ph; Cheung, S-F; Chiapolini, N; Chrzaszcz, M; Ciba, K; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coca, C; Coco, V; Cogan, J; Cogneras, E; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Corvo, M; Counts, I; Couturier, B; Cowan, G A; Craik, D C; Cruz Torres, M; Cunliffe, S; Currie, R; D'Ambrosio, C; Dalseno, J; David, P; David, P N Y; Davis, A; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Decamp, D; Deckenhoff, M; Del Buono, L; Déléage, N; Derkach, D; Deschamps, O; Dettori, F; Di Canto, A; Dijkstra, H; Donleavy, S; Dordei, F; Dorigo, M; Dosil Suárez, A; Dossett, D; Dovbnya, A; 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; Esen, S; Evans, T; Falabella, A; Färber, C; Farinelli, C; Farry, S; Ferguson, D; Fernandez Albor, V; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fiorini, M; Firlej, M; Fitzpatrick, C; Fiutowski, T; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Fu, J; Furfaro, E; Gallas Torreira, A; Galli, D; Gandelman, M; Gandini, P; Gao, Y; Garofoli, J; Garra Tico, J; Garrido, L; Gaspar, C; Gauld, R; Gavardi, L; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gianelle, A; Giani, S; Gibson, V; Giubega, L; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gordon, H; Gotti, C; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Griffith, P; Grillo, L; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hamilton, B; Hampson, T; Han, X; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; Hartmann, T; 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; Hunt, P; Hussain, N; Hutchcroft, D; Hynds, D; Iakovenko, V; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jalocha, J; Jans, E; Jaton, P; Jawahery, A; Jezabek, M; Jing, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Jurik, N; Kaballo, M; Kandybei, S; Kanso, W; Karacson, M; Karbach, T M; Kelsey, M; Kenyon, I R; Ketel, T; Khanji, B; Khurewathanakul, C; Klaver, S; Kochebina, O; Kolpin, M; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucharczyk, M; Kudryavtsev, V; Kurek, K; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanciotti, E; Lanfranchi, G; Langenbruch, C; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Leo, S; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Liles, M; Lindner, R; Linn, C; Lionetto, F; Liu, B; Liu, G; Lohn, S; Longstaff, I; Longstaff, I; Lopes, J H; Lopez-March, N; Lowdon, P; Lu, H; Lucchesi, D; Luisier, J; Luo, H; Lupato, A; Luppi, E; Lupton, O; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Manca, G; Mancinelli, G; Manzali, M; Maratas, J; Marchand, J F; Marconi, U; Marino, P; Märki, R; Marks, J; Martellotti, G; Martens, A; Martín Sánchez, A; Martinelli, M; Martinez Santos, D; Martinez Vidal, F; Martins Tostes, D; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Mazurov, A; McCann, M; McCarthy, J; McNab, A; McNulty, R; McSkelly, B; Meadows, B; Meier, F; Meissner, M; Merk, M; Milanes, D A; Minard, M-N; Molina Rodriguez, J; Monteil, S; Moran, D; Morandin, M; Morawski, P; Mordà, A; Morello, M J; Moron, J; Mountain, R; Muheim, F; Müller, K; Muresan, R; Muster, B; Naik, P; Nakada, T; Nandakumar, R; Nasteva, I; Needham, M; Neri, N; Neubert, S; Neufeld, N; Neuner, M; Nguyen, A D; Nguyen, T D; Nguyen-Mau, C; Nicol, M; Niess, V; Niet, R; Nikitin, N; Nikodem, T; Novoselov, A; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Onderwater, G; Orlandea, M; Otalora Goicochea, J M; Owen, P; Oyanguren, A; Pal, B K; Palano, A; Palombo, F; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Patrignani, C; Pazos Alvarez, A; Pearce, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perez Trigo, E; Perret, P; Perrin-Terrin, M; Pescatore, L; Pesen, E; Petridis, K; Petrolini, A; Picatoste Olloqui, E; Pietrzyk, B; Pilař, T; Pinci, D; Pistone, A; Playfer, S; Plo Casasus, M; Polci, F; Polok, G; Poluektov, A; Polycarpo, E; Popov, A; Popov, D; Popovici, B; Potterat, C; Powell, A; Prisciandaro, J; Pritchard, A; Prouve, C; Pugatch, V; Puig Navarro, A; Punzi, G; Qian, W; Rachwal, B; Rademacker, J H; Rakotomiaramanana, B; Rama, M; Rangel, M S; Raniuk, I; Rauschmayr, N; Raven, G; Redford, S; Reichert, S; Reid, M M; Dos Reis, A C; Ricciardi, S; Richards, A; Rinnert, K; Rives Molina, V; Roa Romero, D A; Robbe, P; Rodrigues, A B; Rodrigues, E; Rodriguez Perez, P; Roiser, S; Romanovsky, V; Romero Vidal, A; Rotondo, M; Rouvinet, J; Ruf, T; Ruffini, F; Ruiz, H; Ruiz Valls, P; Sabatino, G; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salustino Guimaraes, V; Sanchez Mayordomo, C; Sanmartin Sedes, B; Santacesaria, R; Santamarina Rios, C; Santovetti, E; Sapunov, M; Sarti, A; Satriano, C; Satta, A; Savrie, M; Savrina, D; Schiller, M; Schindler, H; Schlupp, M; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schune, M-H; Schwemmer, R; Sciascia, B; Sciubba, A; Seco, M; Semennikov, A; Senderowska, K; Sepp, I; Serra, N; Serrano, J; Sestini, L; Seyfert, P; Shapkin, M; Shapoval, I; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, V; Shires, A; Silva Coutinho, R; Simi, G; Sirendi, M; Skidmore, N; Skwarnicki, T; Smith, N A; Smith, E; Smith, E; Smith, J; Smith, M; Snoek, H; Sokoloff, M D; Soler, F J P; Soomro, F; Souza, D; Souza De Paula, B; Spaan, B; Sparkes, A; Spinella, F; Spradlin, P; Stagni, F; Stahl, S; Steinkamp, O; Stenyakin, O; Stevenson, S; Stoica, S; Stone, S; Storaci, B; Stracka, S; Straticiuc, M; Straumann, U; Stroili, R; Subbiah, V K; Sun, L; Sutcliffe, W; Swientek, K; Swientek, S; Syropoulos, V; Szczekowski, M; Szczypka, P; Szilard, D; Szumlak, T; T'Jampens, S; Teklishyn, M; Tellarini, G; Teodorescu, E; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Tolk, S; Tomassetti, L; Tonelli, D; Topp-Joergensen, S; Torr, N; Tournefier, E; Tourneur, S; Tran, M T; Tresch, M; Tsaregorodtsev, A; Tsopelas, P; Tuning, N; Ubeda Garcia, M; Ukleja, A; Ustyuzhanin, A; Uwer, U; 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; Voss, H; de Vries, J A; Waldi, R; Wallace, C; Wallace, R; Walsh, J; Wandernoth, S; Wang, J; Ward, D R; Watson, N K; Webber, A D; Websdale, D; Whitehead, M; Wicht, J; Wiedner, D; Wiggers, L; Wilkinson, G; Williams, M P; Williams, M; Wilson, F F; Wimberley, J; Wishahi, J; Wislicki, W; Witek, M; Wormser, G; Wotton, S A; Wright, S; Wu, S; Wyllie, K; Xie, Y; Xing, Z; Xu, Z; Yang, Z; Yuan, X; Yushchenko, O; Zangoli, M; Zavertyaev, M; Zhang, F; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhokhov, A; Zhong, L; Zvyagin, A

    The polarisation of prompt [Formula: see text] mesons is measured by performing an angular analysis of [Formula: see text] decays using proton-proton collision data, corresponding to an integrated luminosity of 1.0[Formula: see text], collected by the LHCb detector at a centre-of-mass energy of 7 TeV. The polarisation is measured in bins of transverse momentum [Formula: see text] and rapidity [Formula: see text] in the kinematic region [Formula: see text] and [Formula: see text], and is compared to theoretical models. No significant polarisation is observed.

  5. Determination of the gluon polarisation from open charm production at COMPASS

    Energy Technology Data Exchange (ETDEWEB)

    Koblitz, Susanne

    2009-01-27

    One of the main goals of the COMPASS experiment at CERN is the determination of the gluon polarisation in the nucleon, {delta}G/G. It is determined from spin asymmetries in the scattering of 160GeV/c polarised muons on a polarised LiD target. The gluon polarisation is accessed by the selection of photon-gluon fusion (PGF) events. The PGF-process can be tagged through hadrons with high transverse momenta or through charmed hadrons in the final state. The advantage of the open charm channel is that, in leading order, the PGF-process is the only process for charm production, thus no physical background contributes to the selected data sample. This thesis presents a measurement of the gluon polarisation left angle {delta}g/g right angle from the COMPASS data taken in the years 2002-2004. In the analysis, charm production is tagged through a reconstructed D{sup 0}-meson decaying in D{sup 0}{yields} K{sup -}{pi}{sup +} (and charge conjugates). The reconstruction is done on a combinatorial basis. The background of wrong track pairs is reduced using kinematic cuts to the reconstructed D{sup 0}-candidate and the information on particle identification from the Ring Imaging Cerenkov counter. In addition, the event sample is separated into D{sup 0}-candidates, where a soft pion from the decay of the D{sup *}-meson to a D{sup 0}-meson, is found, and the D{sup 0}-candidates without this tag. Due to the small mass difference between D{sup *}-meson and D{sup 0}-meson the signal purity of the D{sup *}-tagged sample is about 7 times higher than in the untagged sample. The gluon polarisation left angle {delta}g/g right angle is measured from the event asymmetries for the for the different spin configurations of the COMPASS target. To improve the statistical precision of the final results, the events in the final sample are weighted. The use of a signal and a background weight allows the separation of left angle {delta}g/g right angle, and a possible asymmetry in the combinatorial

  6. Determination of the gluon polarisation from open charm production at COMPASS

    International Nuclear Information System (INIS)

    Koblitz, Susanne

    2009-01-01

    One of the main goals of the COMPASS experiment at CERN is the determination of the gluon polarisation in the nucleon, ΔG/G. It is determined from spin asymmetries in the scattering of 160GeV/c polarised muons on a polarised LiD target. The gluon polarisation is accessed by the selection of photon-gluon fusion (PGF) events. The PGF-process can be tagged through hadrons with high transverse momenta or through charmed hadrons in the final state. The advantage of the open charm channel is that, in leading order, the PGF-process is the only process for charm production, thus no physical background contributes to the selected data sample. This thesis presents a measurement of the gluon polarisation left angle Δg/g right angle from the COMPASS data taken in the years 2002-2004. In the analysis, charm production is tagged through a reconstructed D 0 -meson decaying in D 0 → K - π + (and charge conjugates). The reconstruction is done on a combinatorial basis. The background of wrong track pairs is reduced using kinematic cuts to the reconstructed D 0 -candidate and the information on particle identification from the Ring Imaging Cerenkov counter. In addition, the event sample is separated into D 0 -candidates, where a soft pion from the decay of the D * -meson to a D 0 -meson, is found, and the D 0 -candidates without this tag. Due to the small mass difference between D * -meson and D 0 -meson the signal purity of the D * -tagged sample is about 7 times higher than in the untagged sample. The gluon polarisation left angle Δg/g right angle is measured from the event asymmetries for the for the different spin configurations of the COMPASS target. To improve the statistical precision of the final results, the events in the final sample are weighted. The use of a signal and a background weight allows the separation of left angle Δg/g right angle, and a possible asymmetry in the combinatorial background. This method results in an average value of the gluon polarisation

  7. Spontaneous mutation by mutagenic repair of spontaneous lesions in DNA

    International Nuclear Information System (INIS)

    Hastings, P.J.; Quah, S.-K.; Borstel, R.C. von

    1976-01-01

    It is stated that strains of yeast carrying mutations in many of the steps in pathways repairing radiation-induced damage to DNA have enhanced spontaneous mutation rates. Most strains isolated because they have enhanced spontaneous mutation carry mutations in DNA repair systems. This suggests that much spontaneous mutation arises by mutagenic repair of spontaneous lesions. (author)

  8. Polarisation properties of irradiated ammonia (NH3 and ND3) at 1 K and 25 kG

    International Nuclear Information System (INIS)

    Riechert, H.

    1982-11-01

    Dynamic Nuclear Polarisation (DNP) of irradiated ammonia was examined in some detail at 1 K and 25 kG. In continuation of earlier studies conducted in Bonn, it was attempted to gain information about the prevailing mechanism of DNP in this material. Therefore the frequency dependence of DNP in NH 3 , of deuterons and unsubstituted protons in ND 3 , as well as the polarising time tau and the relaxation time T 1 in NH 3 were measured. Also the shape of the deuteron polarisation signal observed in ND 3 is discussed. The polarisation measurements in ND 3 rule out the equal spin temperature (EST) behaviour of proton and deuteron DNP that is observed in most of the currently used target materials. It is attempted to explain the observations with a differential solid state effect model. Results of calculations for NH 3 and ND 3 incorporating the measured EPR-spectra are presented. (orig.)

  9. Leading order determination of the gluon polarisation from DIS events with high-$p_T$ hadron pairs

    CERN Document Server

    Adolph, C; Alexakhin, V Yu; Alexandrov, Yu; Alexeev, G D; Amoroso, A; Antonov, A A; Austregesilo, A; Badelek, B; Balestra, F; Barth, J; Baum, G; Bedfer, Y; Bernhard, J; Bertini, R; Bettinelli, M; Bicker, K; Bieling, J; Birsa, R; Bisplinghoff, J; Bordalo, P; Bradamante, F; Braun, C; Bravar, A; Bressan, A; Burtin, E; Chaberny, D; Chiosso, M; Chung, S U; Cicuttin, A; Crespo, M L; Dalla Torre, S; Das, S; Dasgupta, S S; Denisov, O.Yu; Dhara, L; Donskov, S V; Doshita, N; Duic, V; Dunnweber, W; Dziewiecki, M; Efremov, A; Elia, C; Eversheim, P D; Eyrich, W; Faessler, M; Ferrero, A; Filin, A; Finger, M; jr., M.Finger; Fischer, H; Franco, C; von Hohenesche, N.du Fresne; Friedrich, J M; Garfagnini, R; Gautheron, F; Gavrichtchouk, O P; Gazda, R; Gerassimov, S; Geyer, R; Giorgi, M; Gnesi, I; Gobbo, B; Goertz, S; Grabmuller, S; Grasso, A; Grube, B; Gushterski, R; Guskov, A; Guthorl, T; Haas, F; von Harrach, D; Hedicke, S; Heinsius, F H; Herrmann, F; Hess, C; Hinterberger, F; Horikawa, N; Hoppner, Ch; d'Hose, N; Huber, S; Ishimoto, S; Ivanov, O; Ivanshin, Yu; Iwata, T; Jahn, R; Jasinski, P; Joosten, R; Kabuss, E; Kang, D; Ketzer, B; Khaustov, G V; Khokhlov, Yu.A; Kisselev, Yu; Klein, F; Klimaszewski, K; Koblitz, S; Koivuniemi, J H; Kolosov, V N; Kondo, K; Konigsmann, K; Konorov, I; Konstantinov, V F; Korzenev, A; Kotzinian, A M; Kouznetsov, O; Kramer, M; Kroumchtein, Z V; Kunne, F.; Kurek, K; Lauser, L; Le Goff, J M; Lednev, A A; Lehmann, A; Levorato, S; Lichtenstadt, J; Maggiora, A; Magnon, A; Makke, N; Mallot, G K; Mann, A; Marchand, C; Martin, A; Marzec, J; Matsuda, T; Meyer, W; Michigami, T; Mikhailov, Yu.V; Moinester, M A; Morreale, A; Mutter, A; Nagaytsev, A; Nagel, T; Nassalski, J P; Nerling, F; Neubert, S; Neyret, D; Nikolaenko, V I; Nowak, W D; Nunes, A S; Olshevsky, A G; Ostrick, M; Padee, A; Panknin, R; Panzieri, D; Parsamyan, B; Paul, S.; Perevalova, E; Pesaro, G; Peshekhonov, D V; Piragino, G; Platchkov, S; Pochodzalla, J; Polak, J; Polyakov, V A; Pontecorvo, G; Pretz, J; Procureur, S L; Quaresma, M; Quintans, C; Rajotte, J F; Ramos, S; Rapatsky, V; Reicherz, G; Richter, A; Rocco, E; Rondio, E; Rossiyskaya, N S; Ryabchikov, D I; Samoylenko, V D; Sandacz, A; Sapozhnikov, M G; Sarkar, S.; Savin, I A; Sbrizzai, G; Schiavon, P; Schill, C.; Schluter, T; Schmidt, K; Schmitt, L; Schonning, K; Schopferer, S; Schott, M; Shevchenko, O.Yu; Silva, L; Sinha, L; Sissakian, A N; Slunecka, M; Smirnov, G I; Sosio, S; Sozzi, F; Srnka, A; Stolarski, M; Sulc, M; Sulej, R; Sznajder, P; Takekawa, S; Wolbeek, J.Ter; Tessaro, S; Tessarotto, F; Tkatchev, L G; Uhl, S; Uman, I; Vandenbroucke, M; Virius, M; Vlassov, N V; Wang, L; Windmolders, R; Wislicki, W; Wollny, H; Zaremba, K; Zavertyaev, M; Zemlyanichkina, E; Ziembicki, M; Zhuravlev, N; Zvyagin, A

    2013-01-01

    We present a determination of the gluon polarisation Delta g/g in the nucleon, based on the longitudinal double-spin asymmetry of DIS events with a pair of large transverse-momentum hadrons in the final state. The data were obtained by the COMPASS experiment at CERN using a 160 GeV/c polarised muon beam scattering off a polarised ^6LiD target. The gluon polarisation is evaluated by a Neural Network approach for three intervals of the gluon momentum fraction x_g covering the range 0.04 < x_g < 0.27. The values obtained at leading order in QCD do not show any significant dependence on x_g. Their average is Delta g/g = 0.125 +/- 0.060 (stat.) +/- 0.063 (syst.) at x_g=0.09 and a scale of mu^2 = 3~(GeV/c)^2.

  10. Evaluation of Implant Communication with Polarisation and Unslotted CSMA/CA Protocol in Wireless Body Area Networks

    Directory of Open Access Journals (Sweden)

    Kyung Sup Kwak

    2010-01-01

    Full Text Available The performance of the implant inside a human body with polarisation, distance, and different power settings at the base-station is presented. In addition, the unslotted CSMA/CA protocol is studied for a heterogeneous WBAN.

  11. Heavy flavour corrections to polarised and unpolarised deep-inelastic scattering at 3-loop order

    International Nuclear Information System (INIS)

    Ablinger, J.; Round, M.; Schneider, C.; Hasselhuhn, A.

    2016-11-01

    We report on progress in the calculation of 3-loop corrections to the deep-inelastic structure functions from massive quarks in the asymptotic region of large momentum transfer Q"2. Recently completed results allow us to obtain the O(a"3_s) contributions to several heavy flavour Wilson coefficients which enter both polarised and unpolarised structure functions for lepton-nucleon scattering. In particular, we obtain the non-singlet contributions to the unpolarised structure functions F_2(x,Q"2) and xF_3(x,Q"2) and the polarised structure function g_1(x,Q"2). From these results we also obtain the heavy flavour contributions to the Gross-Llewellyn-Smith and the Bjorken sum rules.

  12. A Future Linear Collider with Polarised Beams: Searches for New Physics

    International Nuclear Information System (INIS)

    Moortgat-Pick, Gudrid

    2003-01-01

    There exists a world-wide consensus for a future e+e- Linear Collider in the energy range between √(s) =500-1000 GeV as the next large facility in HEP. The Linear Collider has a large physics potential for the discovery of new physics beyond the Standard Model and for precision studies of the Standard Model itself. It is well suited to complement and extend the physics program of the LHC. The use of polarised beams at a Linear Collider will be a powerful tool. In this paper we will summarize some highlights of high precision tests of the electroweak theory and of searches for physics beyond the Standard Model at a future Linear Collider with polarised e- and e+ beams

  13. Spin-lattice interactions studied by polarised and unpolarised inelastic scattering application to the invar problem

    Energy Technology Data Exchange (ETDEWEB)

    Brown, P J [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1996-11-01

    A semi-quantitative analysis is given of some of the ways in which spin-lattice interactions can modify the cross-sections observable in neutron scattering experiments. This analysis is applied to the scattering from the invar alloy Fe{sub 65}Ni{sub 35} using a model in which the magnetic moment is a function of the near neighbour separation. This model has been applied to clarify the results of inelastic scattering experiments carried out on Fe{sub 65}Ni{sub 35} using both polarised and unpolarised neutrons. The extra information obtainable using polarised neutrons as well as the difficulties and limitations of the technique for inelastic scattering are discussed. (author) 8 figs., 14 refs.

  14. First experiences of the operational use of a dual-polarisation weather radar in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Saltikoff, Elena; Nevvonen, Ljubov [Finnish Meteorological Institute, Helsinki (Finland)

    2011-06-15

    Many national weather services are currently bringing dual-polarisation radars into operational use, after three decades of its use in research. In Finland, three systems are already running operationally, and the data are integrated into the national weather service infrastructure. This opens up new possibilities for applications, but also sets new challenges for measurement design. Our solution has been to alternate measurements optimized for dual-polarisation with another set of measurements optimized for the best quality of Doppler velocity data. This paper describes how the new measurement schedule was designed, balancing between the different needs of the end-users. Our experience after a few months of usage is illustrated with three case studies in weather situations typical of the Finnish climate. (orig.)

  15. Dynamic. cap alpha. -transfer polarisation potentials and the large angle scattering of /sup 16/O + /sup 28/Si

    Energy Technology Data Exchange (ETDEWEB)

    Hussein, M S; Aleixo, A N; Canto, L F; Carrilho, P; Donangelo, R; Paula, L.S. de

    1987-07-01

    A closed expression is derived for the dynamic ..cap alpha..-transfer polarisation potential for heavy-ion elastic scattering. The back-angle angular distributions for the elastic scattering of /sup 16/O + /sup 28/Si obtained by adding this polarisation potential to the E-18 interaction are shown to be in good agreement with the data if an ..cap alpha..-transfer spectroscopic factor of 0.4 is used.

  16. Computationally Efficient Monte Carlo Simulations for Polarisable Models: Multi-Particle Move Method for Water and Aqueous Electrolytes

    Czech Academy of Sciences Publication Activity Database

    Moučka, F.; Nezbeda, Ivo; Smith, W. R.

    2013-01-01

    Roč. 39, 14-15 (2013), s. 1125-1134 ISSN 0892-7022 Grant - others:GA MŠMT(CZ) LH12019; NSERCC(CA) OGP1041; GA ČR(CZ) GA13-35793P Institutional support: RVO:67985858 Keywords : multi-particle move MC * polarisable water * polarisable electrolytes Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.119, year: 2013

  17. VizieR Online Data Catalog: Polarisation of a sample of late M dwarfs (Morin+, 2010)

    Science.gov (United States)

    Morin, J.; Donati, J.-F.; Petit, P.; Delfosse, X.; Forveille, T.; Jardine, M. M.

    2010-06-01

    We have collected 174 pairs of Stokes I (unpolarised) and V (circularly polarised) spectra with ESPaDOnS at CFHT (2003ASPC..307...41D) between June 2006 and July 2009. All spectra were reduced using the Libre-Esprit pipeline, and the mean I and V line profiles were extracted using the Least-Squares Deconvolution (LSD) technique (Donati et al., 1997MNRAS.291..658D). (3 data files).

  18. A neutron polarisation analysis study of the 'central' peak in single-crystal praseodymium

    International Nuclear Information System (INIS)

    Burke, S.K.; Stirling, W.G.; McEwen, K.A.; Salford Univ.

    1981-01-01

    The technique of neutron polarisation analysis has been used to examine the broad 'central' peak in paramagnetic praseodymium. Measurements over the temperature range 1.2-25 K show that these peaks, observed at reciprocal space positions (Q 1 , 0, 2m + 1) with Q 1 = 0.11 tau 100 , are entirely magnetic in character. The relationship between these short-range magnetic correlations and the long-range antiferromagnetic ordering process is discussed. (author)

  19. First doubly polarised photoproduction on {sup 3}He at the photon beam of MAMI

    Energy Technology Data Exchange (ETDEWEB)

    Aguar Bartolome, Patricia

    2010-11-15

    A first experiment with a polarised {sup 3}He target was carried out in July 2009 at the MAMI accelerator in Mainz in a photon energy range between 200 MeV and 800 MeV. The aim of this measurement was to investigate the Gerasimov-Drell-Hearn sum rule on the neutron. The use of the data obtained with the polarised {sup 3}He target, compared to existing data on the deuteron, gives a complementary and more direct access to the neutron, due to the spin structure of the {sup 3}He. The measurement of the helicity dependence of the inclusive total photoabsorption cross section required a beam of tagged circularly polarised photons incident on the longitudinally polarised {sup 3}He target. The data were taken using the 4{pi} Crystal Ball photon spectrometer in combination with TAPS as a forward wall and complemented by a threshold Cherenkov detector used to on-line suppress the background from electromagnetic events. The development and preparation of the different components of the {sup 3}He experimental setup was an important part of this work and are described in detail in this thesis. The detector system and the analysis method were tested by the measurement of the unpolarised total inclusive photoabsorption cross section on liquid hydrogen. The results obtained are in good agreement with previous published data. Preliminary results of the unpolarised total photoabsorption cross section, as well as the helicity dependent photoabsorption cross section difference on {sup 3}He compared with several theoretical models will also be presented. (orig.)

  20. Orientational analysis of dodecanethiol and p-nitrothiophenol SAMs on metals with polarisation-dependent SFG spectroscopy.

    Science.gov (United States)

    Cecchet, Francesca; Lis, Dan; Guthmuller, Julien; Champagne, Benoît; Caudano, Yves; Silien, Christophe; Mani, Alaa Addin; Thiry, Paul A; Peremans, André

    2010-02-22

    Polarisation-dependent sum frequency generation (SFG) spectroscopy is used to investigate the orientation of molecules on metallic surfaces. In particular, self-assembled monolayers (SAMs) of dodecanethiol (DDT) and of p-nitrothiophenol (p-NTP), grown on Pt and on Au, have been chosen as models to highlight the ability of combining ppp and ssp polarisations sets (representing the polarisation of the involved beams in the conventional order of SFG, Vis and IR beam) to infer orientational information at metallic interfaces. Indeed, using only the ppp set of data, as it is usually done for metallic surfaces, is not sufficient to determine the full molecular orientation. We show here that simply combining ppp and ssp polarisations enables both the tilt and rotation angles of methyl groups in DDT SAMs to be determined. Moreover, for p-NTP, while the SFG active vibrations detected with the ppp polarisation alone provide no orientational information, however, the combination with ssp spectra enables to retrieve the tilt angle of the p-NTP 1,4 axis. Though orientational information obtained by polarisation-dependent measurements has been extensively used at insulating interfaces, we report here their first application to metallic surfaces.

  1. Electromagnetic polarisabilities of the proton in an independent particle potential model

    International Nuclear Information System (INIS)

    Barik, N.; Panda, A.R.

    1996-01-01

    We consider the electric and magnetic polarisabilities of the proton including the valence quark as well as pion dressing effects in an independent quark model with an effective scalar-vector harmonic potential which renders the solvability of relativistic Dirac equations for confined quarks, and has in fact acted as an alternative to the cloudy bag model (CBM). This model which has been applied successfully to a variety of hadronic problems is also observed here to yield the electromagnetic polarisabilities of the proton satisfactorily without any free parameters. The electric and magnetic polarisabilities, including valence quark core and pion cloud effects, obtained here as anti α P =14.074.10 -4 fm 3 and anti β P =3.155.10 -4 fm 3 , are well within the uncertainties of their experimental measurements of (10.9±2.2±1.4).10 -4 fm 3 and (3.3±2.2±1.4).10 -4 fm 3 , respectively and are also in agreement with other model estimations. (orig.)

  2. Electromagnetic polarisabilities of the proton in an independent particle potential model

    Energy Technology Data Exchange (ETDEWEB)

    Barik, N [Utkal Univ., Bhubaneswer (India). P.G. Dept. of Phys.; Dash, B K [Utkal Univ., Bhubaneswer (India). P.G. Dept. of Phys.; Das, P [Department of Physics, Kendrapara College, Kendrapara-754211 (India); Panda, A R [Department of Physics, Kendrapara College, Kendrapara-754211 (India)

    1996-08-19

    We consider the electric and magnetic polarisabilities of the proton including the valence quark as well as pion dressing effects in an independent quark model with an effective scalar-vector harmonic potential which renders the solvability of relativistic Dirac equations for confined quarks, and has in fact acted as an alternative to the cloudy bag model (CBM). This model which has been applied successfully to a variety of hadronic problems is also observed here to yield the electromagnetic polarisabilities of the proton satisfactorily without any free parameters. The electric and magnetic polarisabilities, including valence quark core and pion cloud effects, obtained here as anti {alpha}{sub P}=14.074.10{sup -4} fm{sup 3} and anti {beta}{sub P}=3.155.10{sup -4} fm{sup 3}, are well within the uncertainties of their experimental measurements of (10.9{+-}2.2{+-}1.4).10{sup -4} fm{sup 3} and (3.3{+-}2.2{+-}1.4).10{sup -4} fm{sup 3}, respectively and are also in agreement with other model estimations. (orig.).

  3. Searches for the Anomalous Photon Polarisation in Radiative B Decays at LHCb

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00455305

    This thesis is exploring the measurements of the photon polarisation in radiative $B$ decays at LHCb, which are mediated through $b\\to s\\gamma$ transitions. To ensure optimal physics performance, procedures to align the LHCb detector and to monitor the alignment quality over time are presented. Using data corresponding to an integrated luminosity of $3~\\text{fb}^{-1}$, collected in the year of 2011 at the centre-of-energy $\\sqrt{s} = 7$~TeV and the year of 2012 at $\\sqrt{s} = 8$~TeV in proton-proton collisions, the photon polarisation parameter $A^\\Delta$, which is related to the ratio of right- over left-handed photon polarisation amplitudes in $b\\to s\\gamma$ transitions, is measured by performing an untagged time-dependent analysis of more than $4000$ $B_s^0\\to \\phi\\gamma$ decays. From an unbinned simultaneous fit to the $B_s^0\\to\\phi\\gamma$ and the control channel $B^0\\to{K^*}^0\\gamma$ data samples, a value of $A^\\Delta = -0.98^{~+0.46}_{~-0.52}\\text{(stat.)}^{~+0.23}_{~-0.20}\\text{(syst.)}$ is measured. T...

  4. Studies of quarkonium production and polarisation with early data at ATLAS

    CERN Document Server

    Price, Darren David

    2008-01-01

    This thesis presents a range of studies of the production cross-section and polarisation of quarkonium at the ATLAS experiment at the LHC. As data-taking has not yet begun, these studies are conducted on fully simulated and reconstructed Monte Carlo samples. The main studies of this thesis are an analysis of the production cross-sections of J/psi and Upsilon mesons at ATLAS with 10 pb^-1 of data, along with an analysis of the polarisation of the J/psi and Upsilon that can provide information towards understanding the underlying QCD production mechanism. In addition, we are able to predict the observability of the three chi_c states through its radiative decays to J/psi. I present details of a new method of data-driven muon reconstruction efficiency determination using Inner Detector tracking information in quarkonium decays, and studies into the uses of quarkonia for detector performance, commissioning and data quality monitoring. Using a new method of measuring the polarisation distribution that reduces syst...

  5. Measurement of the W-boson polarisation in top-quark decays with the ATLAS detector

    International Nuclear Information System (INIS)

    Knue, Andrea Helen

    2013-01-01

    A measurement of the W-boson polarisation in top-quark decays is presented. The top-antitop events were produced in proton-proton collisions at a centre-of-mass energy of √(s)=7 TeV at the LHC. The data set corresponds to an integrated luminosity of ∫ Ldt=4.7 fb -1 and was collected by the ATLAS experiment. The measurement was performed in the lepton+jets channel which is characterised by an isolated electron or muon, missing transverse energy and at least four jets. One of the jets has to be identified as a b-jet. The W-boson polarisation was studied using the angular distribution of the charged lepton in the rest frame of the W-boson. The event is fully reconstructed using a kinematic likelihood fit. The fractions of left-handed, right-handed and longitudinally polarised W-bosons were estimated from the data distribution using a binned likelihood fit. The W-helicity fractions obtained from the combined likelihood fit are: F 0 =0.659±0.02(stat.)±0.071(syst.), F L =0.317±0.014(stat.)±0.026 (syst.), F R =0.024±0.019(stat.)±0.057(syst.). Limits on anomalous Wtb-couplings were set. All results are in good agreement with the Standard Model predictions.

  6. Case of spontaneous ventriculocisternostomy

    Energy Technology Data Exchange (ETDEWEB)

    Yamane, Kanji; Yoshimoto, Hisanori; Harada, Kiyoshi; Uozumi, Tohru [Hiroshima Univ. (Japan). School of Medicine; Kuwabara, Satoshi

    1983-05-01

    The authors experienced a case of spontaneous ventriculocisternostomy diagnosed by CT scan with metrizamide and Conray. Patient was 23-year-old male who had been in good health until one month before admission, when he began to have headache and tinnitus. He noticed bilateral visual acuity was decreased about one week before admission and vomiting appeared two days before admission. He was admitted to our hospital because of bilateral papilledema and remarkable hydrocephalus diagnosed by CT scan. On admission, no abnormal neurological signs except for bilateral papilledema were noted. Immediately, right ventricular drainage was performed. Pressure of the ventricle was over 300mmH/sub 2/O and CSF was clear. PVG and PEG disclosed an another cavity behind the third ventricle, which was communicated with the third ventricle, and occlusion of aqueduct of Sylvius. Metrizamide CT scan and Conray CT scan showed a communication between this cavity and quadrigeminal and supracerebellar cisterns. On these neuroradiological findings, the diagnosis of obstructive hydrocephalus due to benign aqueduct stenosis accompanied with spontaneous ventriculocisternostomy was obtained. Spontaneous ventriculocisternostomy was noticed to produce arrest of hydrocephalus, but with our case, spontaneous regression of such symptoms did not appeared. By surgical ventriculocisternostomy (method by Torkildsen, Dandy, or Scarff), arrest of hydrocephalus was seen in about 50 to 70 per cent, which was the same results as those of spontaneous ventriculocisternostomy. It is concluded that VP shunt or VA shunt is thought to be better treatment of obstructive hydrocephalus than the various kinds of surgical ventriculocisternostomy.

  7. Maternal allergen immunisation to prevent sensitisation in offspring: Th2-polarising adjuvants are more efficient than a Th1-polarising adjuvant in mice

    Directory of Open Access Journals (Sweden)

    Melkild Ingrid

    2010-03-01

    Full Text Available Abstract Background Allergy has been an increasing problem in several parts of the world. Prenatal exposure to allergen and microbial components may affect the development of allergies in childhood, as indicated by epidemiological and experimental studies. We investigated the capacity for allergic sensitisation in offspring after induction of a Th1- or a Th2-polarised immune response to the same allergen in mothers during pregnancy. Results During pregnancy, mice were immunised with ovalbumin (OVA given with either one of the Th2-adjuvants pertussis toxin (PT or Al(OH3 (aluminium hydroxide, or with the Th1 adjuvant CpG. Offspring were immunised with OVA in Al(OH3 as young adults. Serum and supernatants from ex vivo stimulated or non-stimulated spleen cells from mothers and offspring were analysed for OVA-specific antibodies and cytokines, respectively. Mothers immunised with OVA together with either Al(OH3 or PT had increased levels of OVA-specific IgE and IgG1 compared to naive mothers, whereas mothers immunised with OVA together with CpG had increased levels of OVA-specific IgG2a compared to naive mothers. In general the highest levels of IL-5, IL-10, and IFNγ were observed in spleen cells from mothers immunised with PT and OVA. Upon immunisation, offspring from mothers immunised with OVA and either PT or Al(OH3 showed reduced levels of OVA-specific IgE and IgG1 and increased levels of OVA-specific IgG2a antibodies compared to offspring from naive mothers. Maternal immunisation with CpG and OVA did not affect antibody responses in offspring. Conclusion Allergic sensitisation in the offspring was affected by the type of adjuvant used for immunisation of the mothers with the same allergen. Th2 polarisation of the immune response in the mothers was found to give reduced IgE levels upon sensitisation of the offspring, whereas no reduction was achieved with Th1 polarisation in the mothers.

  8. Perturbation approach to design of circularly polarised microstrip antennas

    Science.gov (United States)

    Lo, Y. T.; Richards, W. F.

    1981-05-01

    One of the most interesting applications of microstrip antennas is its use for transmitting or receiving circularly polarized (CP) waves. A description is given of a simple but accurate method to determine the critical dimensions needed to produce circular polarization for nearly square and nearly circular microstrip antennas. Shen (1981) in connection with the determination of the proper dimensions of an elliptical patch CP microstrip antenna first expressed the modal field in terms of Mathieu functions. To avoid the complicated numerical computation of the Mathieu functions, he approximated these functions in terms of Bessel functions. It is pointed out that the computation of Mathieu functions, or their approximate expressions can be avoided altogether if a perturbation method is applied to find the resonant frequencies of the two orthogonal modes. The implementation of this approach is demonstrated.

  9. Spontaneous tension haemopneumothorax.

    Science.gov (United States)

    Patterson, Benjamin Oliver; Itam, Sarah; Probst, Fey

    2008-10-31

    We present a patient with sudden onset progressive shortness of breath and no history of trauma, who rapidly became haemodynamically compromised with a pneumothorax and pleural effusion seen on chest radiograph. He was treated for spontaneous tension pneumothorax but this was soon revealed to be a tension haemopneumothorax. He underwent urgent thoracotomy after persistent bleeding to explore an apical vascular abnormality seen on CT scanning. To our knowledge this is the first such case reported.Aetiology and current approach to spontaneous haemothorax are discussed briefly.

  10. Spontaneous Atraumatic Mediastinal Hemorrhage

    Directory of Open Access Journals (Sweden)

    Morkos Iskander BSc, BMBS, MRCS, PGCertMedEd

    2013-04-01

    Full Text Available Spontaneous atraumatic mediastinal hematomas are rare. We present a case of a previously fit and well middle-aged lady who presented with acute breathlessness and an increasing neck swelling and spontaneous neck bruising. On plain chest radiograph, widening of the mediastinum was noted. The bruising was later confirmed to be secondary to mediastinal hematoma. This life-threatening diagnostic conundrum was managed conservatively with a multidisciplinary team approach involving upper gastrointestinal and thoracic surgeons, gastroenterologists, radiologists, intensivists, and hematologists along with a variety of diagnostic modalities. A review of literature is also presented to help surgeons manage such challenging and complicated cases.

  11. Spontaneous tension haemopneumothorax

    Directory of Open Access Journals (Sweden)

    Itam Sarah

    2008-10-01

    Full Text Available Abstract We present a patient with sudden onset progressive shortness of breath and no history of trauma, who rapidly became haemodynamically compromised with a pneumothorax and pleural effusion seen on chest radiograph. He was treated for spontaneous tension pneumothorax but this was soon revealed to be a tension haemopneumothorax. He underwent urgent thoracotomy after persistent bleeding to explore an apical vascular abnormality seen on CT scanning. To our knowledge this is the first such case reported. Aetiology and current approach to spontaneous haemothorax are discussed briefly.

  12. Grooming behavior of spontaneously hypertensive rats

    NARCIS (Netherlands)

    Buuse, M. van den; Jong, Wybren de

    1987-01-01

    In an open field spontaneously hypertensive rats (SHR) exhibited lower scores for grooming when compared to their normotensive controls, the Wistar Kyoto rats (WKY). After i.c.v. injection of 1 μg ACTH1–24 cumulative 50-min grooming scores were lower in SHR. Analysis of subscores indicated that the

  13. Unified gauge theories with spontaneous symmetry breaking

    International Nuclear Information System (INIS)

    MacDowell, S.W.

    1975-01-01

    Unified gauge theories with spontaneous symmetry breaking are studied with a view to renormalize quantum field theory. Georgi-Glashow and Weinberg-Salam models to unify weak and electromagnetic interactions are discussed in detail. Gauge theories of strong interactions are also considered [pt

  14. Magnetic rotational polarisation in plasmas. Application to the measurement of electronic density; Polarisation rotatoire magnetique dans les plasmas. Application a la mesure de la densite electronique

    Energy Technology Data Exchange (ETDEWEB)

    Consoli, Terenzio; Dagai, Michel [Commissariat a l' energie atomique et aux energies alternatives - CEA (France)

    1960-07-01

    The rotation of a linearly polarised wave passing through a layer of plasma is determined. A network of curves enables these results to be applied to the electronic density measurement in a plasma during its evolution. Reprint of a paper published in Comptes rendus des seances de l'Academie des Sciences, t. 250, p. 1010-1012, sitting of 8 February 1960 [French] On determine la rotation d'une onde polarisee lineairement, traversant une couche de plasma. Un reseau de courbes permet d'appliquer ces resultats a la mesure de la densite electronique d'un plasma en evolution. Reproduction d'un article publie dans les Comptes rendus des seances de l'Academie des Sciences, t. 250, p. 1010-1012, seance du 8 fevrier 1960.

  15. Spontaneous rib fractures.

    Science.gov (United States)

    Katrancioglu, Ozgur; Akkas, Yucel; Arslan, Sulhattin; Sahin, Ekber

    2015-07-01

    Other than trauma, rib fracture can occur spontaneously due to a severe cough or sneeze. In this study, patients with spontaneous rib fractures were analyzed according to age, sex, underlying pathology, treatment, and complications. Twelve patients who presented between February 2009 and February 2011 with spontaneous rib fracture were reviewed retrospectively. The patients' data were evaluated according to anamnesis, physical examination, and chest radiographs. The ages of the patients ranged from 34 to 77 years (mean 55.91 ± 12.20 years), and 7 (58.4%) were male. All patients had severe cough and chest pain. The fractures were most frequently between 4th and 9th ribs; multiple rib fractures were detected in 5 (41.7%) patients. Eight (66.7%) patients had chronic obstructive pulmonary disease, 2 (16.7%) had bronchial asthma, and 2 (16.7%) had osteoporosis. Bone densitometry revealed a high risk of bone fracture in all patients. Patients with chronic obstructive pulmonary disease or bronchial asthma had been treated with high-dose steroids for over a year. Spontaneous rib fracture due to severe cough may occur in patients with osteoporosis, chronic obstructive pulmonary disease, or bronchial asthma, receiving long-term steroid therapy. If these patients have severe chest pain, chest radiography should be performed to check for bone lesions. © The Author(s) 2015.

  16. [Spontaneous bacterial peritonitis].

    Science.gov (United States)

    Velkey, Bálint; Vitális, Eszter; Vitális, Zsuzsanna

    2017-01-01

    Spontaneous bacterial peritonitis occurs most commonly in cirrhotic patients with ascites. Pathogens get into the circulation by intestinal translocation and colonize in peritoneal fluid. Diagnosis of spontaneous bacterial peritonitis is based on elevated polymorphonuclear leukocyte count in the ascites (>0,25 G/L). Ascites culture is often negative but aids to get information about antibiotic sensitivity in positive cases. Treatment in stable patient can be intravenous then orally administrated ciprofloxacin or amoxicillin/clavulanic acid, while in severe cases intravenous III. generation cephalosporin. Nosocomial spontaneous bacterial peritonitis often caused by Gram-positive bacteria and multi-resistant pathogens can also be expected thus carbapenem should be the choice of the empiric treatment. Antibiotic prophylaxis should be considered. Norfloxacin is used most commonly, but changes are expected due to increase in quinolone resistance. As a primary prophylaxis, a short-term antibiotic treatment is recommended after gastrointestinal bleeding for 5 days, while long-term prophylaxis is for patients with low ascites protein, and advanced disease (400 mg/day). Secondary prophylaxis is recommended for all patients recovered from spontaneous bacterial peritonitis. Due to increasing antibiotic use of antibiotics prophylaxis is debated to some degree. Orv. Hetil., 2017, 158(2), 50-57.

  17. Large solid-angle polarisation analysis at thermal neutron wavelengths using a sup 3 He spin filter

    CERN Document Server

    Heil, W; Cywinski, R; Humblot, H; Ritter, C; Roberts, T W; Stewart, J R

    2002-01-01

    The strongly spin-dependent absorption of neutrons in nuclear spin-polarised sup 3 He opens up the possibility of polarising neutrons from reactors and spallation sources over the full kinematical range of cold, thermal and hot neutrons. In this paper we describe the first large solid-angle polarisation analysis measurement using a sup 3 He neutron spin filter at thermal neutron wavelengths (lambda=2.5 A). This experiment was performed on the two-axis diffractometer D1B at the Institut Laue-Langevin using a banana-shaped filter cell (530 cm sup 3 ) filled with sup 3 He gas with a polarisation of P=52% at a pressure of 2.7 bar. A comparison is made with a previous measurement on D7 using a cold neutron beam on the same sample, i.e. amorphous ErY sub 6 Ni sub 3. Using uniaxial polarisation analysis both the nuclear and magnetic cross-sections could be extracted over the range of scattering-vectors [0.5<=Q(A sup - sup 1)<=3.5]. The results are in qualitative and quantitative agreement with the D7-data, whe...

  18. International Conference on Polarised Neutrons for Condensed Matter Investigations (PNCMI 2016)

    International Nuclear Information System (INIS)

    2017-01-01

    The present volume of the Journal of Physics: Conference Series represents Proceedings of the 11th International Conference on Polarised Neutrons for Condensed Matter Investigation (PNCMI) held in Freising, Germany from July 4–7, 2016. The conference attended by more than 120 scientists from various academic, government, and industrial institutions in Europe, Asia and the Americas was organized by the Jülich Centre for Neutron Science of the Forschungszentrum Jülich. The PNCMI-2016 continuoued the successful previous conferences in this series covering the latest condensed matter investigations using polarised neutrons and state-of-the-art methodologies, from effective polarization of neutron beams to wide-angle polarization analysis, as well as applications for novel instrumentation and experiments, with emphasis on prospects for new science and new instrument concepts. The conference program included invited and contributed oral presentations and posters which demonstrated the activities using polarized neutrons all over the world and showed the deep interest in developing the topic. The presentations tackled all area of science including multiferroic and chirality, strongly correlated electron systems, superconductors, frustrated and disordered systems, magnetic nanomaterials, thin films and multilayers, soft matter and biology, imaging, as well as further developments in polarized neutron techniques and methods, including nuclear polarisation, Larmor techniques and depolarisation methods.. We would like to thank all speakers for their presentations and all attendees for their participation. We would also like to gratefully acknowledge the financial support by J-PARC and AIRBUS DS as Premium Sponsors and Swiss Neutronics, ISIS, LLB, PSI and Mirrotron as Standard Sponsors of this conference. The next PNCMI will take place in Great Britain in 2018 and will be organized by ISIS. Alexander Ioffe (Conference Chair) Thomas Gutberlet (Conference Secretary) (paper)

  19. Chitosan drives anti-inflammatory macrophage polarisation and pro-inflammatory dendritic cell stimulation

    Directory of Open Access Journals (Sweden)

    MI Oliveira

    2012-07-01

    Full Text Available Macrophages and dendritic cells (DC share the same precursor and play key roles in immunity. Modulation of their behaviour to achieve an optimal host response towards an implanted device is still a challenge. Here we compare the differentiation process and polarisation of these related cell populations and show that they exhibit different responses to chitosan (Ch, with human monocyte-derived macrophages polarising towards an anti-inflammatory phenotype while their DC counterparts display pro-inflammatory features. Macrophages and DC, whose interactions with biomaterials are frequently analysed using fully differentiated cells, were cultured directly on Ch films, rather than exposed to the polymer after complete differentiation. Ch was the sole stimulating factor and activated both macrophages and DC, without leading to significant T cell proliferation. After 10 d on Ch, macrophages significantly down-regulated expression of pro-inflammatory markers, CD86 and MHCII. Production of pro-inflammatory cytokines, particularly TNF-α, decreased with time for cells cultured on Ch, while anti-inflammatory IL-10 and TGF-β1, significantly increased. Altogether, these results suggest an M2c polarisation. Also, macrophage matrix metalloproteinase activity was augmented and cell motility was stimulated by Ch. Conversely, DC significantly enhanced CD86 expression, reduced IL-10 secretion and increased TNF-α and IL-1β levels. Our findings indicate that cells with a common precursor may display different responses, when challenged by the same biomaterial. Moreover, they help to further comprehend macrophage/DC interactions with Ch and the balance between pro- and anti-inflammatory signals associated with implant biomaterials. We propose that an overall pro-inflammatory reaction may hide the expression of anti-inflammatory cytokines, likely relevant for tissue repair/regeneration.

  20. Proposal for a source of polarized protons; Projet de source de protons polarises

    Energy Technology Data Exchange (ETDEWEB)

    Abragam, A.; Winter, J. M. [Commissariat a l' energie atomique et aux energies alternatives - CEA, Centre d' Etudes Nucleaires de Saclay, BP2, Gif-sur-Yvette (France)

    1959-07-01

    Proposal for a source of polarized protons based on the theory of adiabatic fast passage due to F. Bloch. Reprint of a paper published in 'Physical review letters', vol 1, n. 10, 15 Nov 1958, p. 374-375 [French] On propose une methode nouvelle pour la realisation d'une source de protons polarises basee sur la theorie du passage adiabatique de F. Bloch. Reproduction d'un article publie dans 'Physical review letters', vol 1, n. 10, 15 nov 1958, p. 374-375.

  1. Macrophage polarisation: an immunohistochemical approach for identifying M1 and M2 macrophages.

    Directory of Open Access Journals (Sweden)

    Mário Henrique M Barros

    Full Text Available Macrophage polarization is increasingly recognised as an important pathogenetic factor in inflammatory and neoplastic diseases. Proinflammatory M1 macrophages promote T helper (Th 1 responses and show tumoricidal activity. M2 macrophages contribute to tissue repair and promote Th2 responses. CD68 and CD163 are used to identify macrophages in tissue sections. However, characterisation of polarised macrophages in situ has remained difficult. Macrophage polarisation is regulated by transcription factors, pSTAT1 and RBP-J for M1, and CMAF for M2. We reasoned that double-labelling immunohistochemistry for the detection of macrophage markers together with transcription factors may be suitable to characterise macrophage polarisation in situ. To test this hypothesis, we have studied conditions associated with Th1- and Th2-predominant immune responses: infectious mononucleosis and Crohn's disease for Th1 and allergic nasal polyps, oxyuriasis, wound healing and foreign body granulomas for predominant Th2 response. In all situations, CD163+ cells usually outnumbered CD68+ cells. Moreover, CD163+ cells, usually considered as M2 macrophages, co-expressing pSTAT1 and RBP-J were found in all conditions examined. The numbers of putative M1 macrophages were higher in Th1- than in Th2-associated diseases, while more M2 macrophages were seen in Th2- than in Th1 related disorders. In most Th1-related diseases, the balance of M1 over M2 cells was shifted towards M1 cells, while the reverse was observed for Th2-related conditions. Hierarchical cluster analysis revealed two distinct clusters: cluster I included Th1 diseases together with cases with high numbers of CD163+pSTAT1+, CD68+pSTAT1+, CD163+RBP-J+ and CD68+RBP-J+ macrophages; cluster II comprised Th2 conditions together with cases displaying high numbers of CD163+CMAF+ and CD68+CMAF+ macrophages. These results suggest that the detection of pSTAT1, RBP-J, and CMAF in the context of CD68 or CD163 expression is a

  2. Measurement of top quark polarisation in t-channel single top quark production

    OpenAIRE

    CMS Collaboration

    2015-01-01

    Journal of High Energy Physics 2016.4 (2016): 073 reproduced by permission of Scuola Internazionale Superiore di Studi Avanzati (SISSA) Artículo escrito por un elevado número de autores, sólo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiera, y los autores pertenecientes a la UAM A first measurement of the top quark spin asymmetry, sensitive to the top quark polarisation, in t-channel single top quark production is presented. It is based o...

  3. Compact broadband circularly polarised slot antenna for universal UHF RFID readers

    DEFF Research Database (Denmark)

    Xu, Bo; Zhang, Shuai; Liu, Yusha

    2015-01-01

    A compact broadband circularly polarised (CP) slot antenna is designed for universal ultra-high-frequency (UHF) radio frequency identification (RFID) readers. The antenna consists of an L-shaped metal strip and a square-slot-loaded ground plane with four tuning stubs. The total size is 100 mm×100mm......×1.6 mm. The measured –10 dB impedance bandwidth is 40.7% (772–1166 MHz) and the measured 3 dB axial ratio (AR) bandwidth is 13.9% (840–965 MHz). Both the impedance and AR bandwidth cover the worldwide UHF RFID band....

  4. Separation of coherent and incoherent scattering in liquid para-H{sub 2} by polarisation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Hernandez, M; Mompean, F J [Madrid Univ. (Spain); Schaerpf, O; Andersen, K H [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France); Fak, B [CEA Centre d` Etudes de Grenoble, 38 (France)

    1997-04-01

    In the 1960 IAEA Symposium on Neutron Scattering, Sarma presented his theoretical study on the scattering of cold neutrons by liquid hydrogen and demonstrated how the intimate coupling between nuclear and rotational degrees of freedom finally results in the possibility of observing collective modes from this material, which to many neutron scatterers is synonymous with `incoherent`. This problem is investigated with polarised neutrons to gain access to a limited region of the (Q,E) space where the collective response from this liquid is found. (author).

  5. Macrophage polarisation: an immunohistochemical approach for identifying M1 and M2 macrophages.

    Science.gov (United States)

    Barros, Mário Henrique M; Hauck, Franziska; Dreyer, Johannes H; Kempkes, Bettina; Niedobitek, Gerald

    2013-01-01

    Macrophage polarization is increasingly recognised as an important pathogenetic factor in inflammatory and neoplastic diseases. Proinflammatory M1 macrophages promote T helper (Th) 1 responses and show tumoricidal activity. M2 macrophages contribute to tissue repair and promote Th2 responses. CD68 and CD163 are used to identify macrophages in tissue sections. However, characterisation of polarised macrophages in situ has remained difficult. Macrophage polarisation is regulated by transcription factors, pSTAT1 and RBP-J for M1, and CMAF for M2. We reasoned that double-labelling immunohistochemistry for the detection of macrophage markers together with transcription factors may be suitable to characterise macrophage polarisation in situ. To test this hypothesis, we have studied conditions associated with Th1- and Th2-predominant immune responses: infectious mononucleosis and Crohn's disease for Th1 and allergic nasal polyps, oxyuriasis, wound healing and foreign body granulomas for predominant Th2 response. In all situations, CD163+ cells usually outnumbered CD68+ cells. Moreover, CD163+ cells, usually considered as M2 macrophages, co-expressing pSTAT1 and RBP-J were found in all conditions examined. The numbers of putative M1 macrophages were higher in Th1- than in Th2-associated diseases, while more M2 macrophages were seen in Th2- than in Th1 related disorders. In most Th1-related diseases, the balance of M1 over M2 cells was shifted towards M1 cells, while the reverse was observed for Th2-related conditions. Hierarchical cluster analysis revealed two distinct clusters: cluster I included Th1 diseases together with cases with high numbers of CD163+pSTAT1+, CD68+pSTAT1+, CD163+RBP-J+ and CD68+RBP-J+ macrophages; cluster II comprised Th2 conditions together with cases displaying high numbers of CD163+CMAF+ and CD68+CMAF+ macrophages. These results suggest that the detection of pSTAT1, RBP-J, and CMAF in the context of CD68 or CD163 expression is a suitable tool for

  6. Collins and Sivers asymmetries in muonproduction of pions and kaons off transversely polarised proton

    CERN Document Server

    Adolph, C.; Alexeev, M G; Alexeev, G D; Amoroso, A; Andrieux, V; Anosov, V; Austregesilo, A; Badełek, B; Balestra, F; Barth, J; Baum, G; Beck, R; Bedfer, Y; Berlin, A; Bernhard, J; Bicker, K; Bieling, J; Birsa, R; Bisplinghoff, J; Bodlak, M; Boer, M; Bordalo, P; Bradamante, F; Braun, C; Bressan, A; Büchele, M; Burtin, E; Capozza, L; Chiosso, M; Chung, S U; Cicuttin, A; Crespo, M L; Curiel, Q; Dalla Torre, S; Dasgupta, S S; Dasgupta, S; Denisov, O Yu; Donskov, S V; Doshita, N; Duic, V; Dünnweber, W; Dziewiecki, M; Efremov, A; Elia, C; Eversheim, P D; Eyrich, W; Faessler, M; Ferrero, A; Filin, A; Finger, M; Finger jr , M; Fischer, H; Franco, C; du Fresne von Hohenesche, N; Friedrich, J M; Frolov, V; Gautheron, F; Gavrichtchouk, O P; Gerassimov, S; Geyer, R; Gnesi, I; Gobbo, B; Goertz, S; Gorzellik, M; Grabmüller, S; Grasso, A; Grube, B; Grussenmeyer, T; Guskov, A; Guthörl, T; Haas, F; von Harrach, D; Hahne, D; Hashimoto, R; Heinsius, F H; Herrmann, F; Hinterberger, F; Höppner, Ch; Horikawa, N; d'Hose, N; Huber, S; Ishimoto, S; Ivanov, A; Ivanshin, Yu; Iwata, T; Jahn, R; Jary, V; Jasinski, P; Jörg, P; Joosten, R; Kabuß, E; Ketzer, B; Khaustov, G V; Khokhlov, Yu A; Kisselev, Yu; Klein, F; Klimaszewski, K; Koivuniemi, J H; Kolosov, V N; Kondo, K; Königsmann, K; Konorov, I; Konstantinov, V F; Kotzinian, A M; Kouznetsov, O; Krämer, M; Kroumchtein, Z V; Kuchinski, N; Kunne, F; Kurek, K; Kurjata, R P; Lednev, A A; Lehmann, A; Levillain, M; Levorato, S; Lichtenstadt, J; Maggiora, A; Magnon, A; Makke, N; Mallot, G K; Marchand, C; Martin, A; Marzec, J; Matousek, J; Matsuda, H; Matsuda, T; Meshcheryakov, G; Meyer, W; Michigami, T; Mikhailov, Yu V; Miyachi, Y; Nagaytsev, A; Nagel, T; Nerling, F; Neubert, S; Neyret, D; Nikolaenko, V I; Novy, J; Nowak, W -D; Nunes, A S; Olshevsky, A G; Orlov, I; Ostrick, M; Panknin, R; Panzieri, D; Parsamyan, B; Paul, S; Peshekhonov, D V; Platchkov, S; Pochodzalla, J; Polyakov, V A; Pretz, J; Quaresma, M; Quintans, C; Ramos, S; Regali, C; Reicherz, G; Rocco, E; Rossiyskaya, N S; Ryabchikov, D I; Rychter, A; Samoylenko, V D; Sandacz, A; Sarkar, S; Savin, I A; Sbrizzai, G; Schiavon, P; Schill, C; Schlüter, T; Schmidt, K; Schmieden, H; Schönning, K; Schopferer, S; Schott, M; Shevchenko, O Yu; Silva, L; Sinha, L; Sirtl, S; Slunecka, M; Sosio, S; Sozzi, F; Srnka, A; Steiger, L; Stolarski, M; Sulc, M; Sulej, R; Suzuki, H; Szabelski, A; Szameitat, T; Sznajder, P; Takekawa, S; ter Wolbeek, J; Tessaro, S; Tessarotto, F; Thibaud, F; Uhl, S; Uman, I; Virius, M; Wang, L; Weisrock, T; Wilfert, M; Windmolders, R; Wollny, H; Zaremba, K; Zavertyaev, M; Zemlyanichkina, E; Ziembicki, M; Zink, A

    2015-03-31

    Measurements of the Collins and Sivers asymmetries for charged pions and charged and neutral kaons produced in semi-inclusive deep-inelastic scattering of high energy muons off transversely polarised protons are presented. The results were obtained using all the available COMPASS proton data, which were taken in the years 2007 and 2010. The Collins asymmetries exhibit in the valence region a non-zero signal for pions and there are hints of non-zero signal also for kaons. The Sivers asymmetries are found to be positive for positive pions and kaons and compatible with zero otherwise.

  7. Measurement of the Collins and Sivers asymmetries on transversely polarised protons

    CERN Document Server

    Alekseev, M.G.; Alexandrov, Yu.; Alexeev, G.D.; Amoroso, A.; Austregesilo, A.; Badelek, B.; Balestra, F.; Ball, J.; Barth, J.; Baum, G.; Bedfer, Y.; Bernhard, J.; Bertini, R.; Bettinelli, M.; Birsa, R.; Bisplinghoff, J.; Bordalo, P.; Bradamante, F.; Bravar, A.; Bressan, A.; Brona, G.; Burtin, E.; Bussa, M.P.; Chaberny, D.; Chiosso, M.; Chung, S.U.; Cicuttin, A.; Colantoni, M.; Crespo, M.L.; Dalla Torre, S.; Das, S.; Dasgupta, S.S.; Denisov, O.Yu.; Dhara, L.; Diaz, V.; Donskov, S.V.; Doshita, N.; Duic, V.; Dunnweber, W.; Efremov, A.; El Alaoui, A.; Elia, C.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Filin, A.; Finger, M.; Finger, M., jr.; Fischer, H.; Franco, C.; Friedrich, J.M.; Garfagnini, R.; Gautheron, F.; Gavrichtchouk, O.P.; Gazda, R.; Gerassimov, S.; Geyer, R.; Giorgi, M.; Gnesi, I.; Gobbo, B.; Goertz, S.; Grabmuller, S.; Grasso, A.; Grube, B.; Gushterski, R.; Guskov, A.; Haas, F.; von Harrach, D.; Hasegawa, T.; Heinsius, F.H.; Hermann, R.; Herrmann, F.; Hess, C.; Hinterberger, F.; Horikawa, N.; Hoppner, Ch.; d'Hose, N.; Ilgner, C.; Ishimoto, S.; Ivanov, O.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jasinski, P.; Jegou, G.; Joosten, R.; Kabuss, E.; Kafer, W.; Kang, D.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu.A.; Kiefer, J.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koblitz, S.; Koivuniemi, J.H.; Kolosov, V.N.; Komissarov, E.V.; Kondo, K.; Konigsmann, K.; Konopka, R.; Konorov, I.; Konstantinov, V.F.; Korzenev, A.; Kotzinian, A.M.; Kouznetsov, O.; Kowalik, K.; Kramer, M.; Kral, A.; Kroumchtein, Z.V.; Kuhn, R.; Kunne, F.; Kurek, K.; Lauser, L.; Le Goff, J.M.; Lednev, A.A.; Lehmann, A.; Levorato, S.; Lichtenstadt, J.; Liska, T.; Maggiora, A.; Maggiora, M.; Magnon, A.; Mallot, G.K.; Mann, A.; Marchand, C.; Martin, A.; Marzec, J.; Massmann, F.; Matsuda, T.; Meyer, W.; Michigami, T.; Mikhailov, Yu.V.; Moinester, M.A.; Mutter, A.; Nagaytsev, A.; Nagel, T.; Nassalski, J.; Negrini, T.; Nerling, F.; Neubert, S.; Neyret, D.; Nikolaenko, V.I.; Nunes, A.S.; Olshevsky, A.G.; Ostrick, M.; Padee, A.; Panknin, R.; Panzieri, D.; Parsamyan, B.; Paul, S.; Pawlukiewicz-Kaminska, B.; Perevalova, E.; Pesaro, G.; Peshekhonov, D.V.; Piragino, G.; Platchkov, S.; Pochodzalla, J.; Polak, J.; Polyakov, V.A.; Pontecorvo, G.; Pretz, J.; Quintans, C.; Rajotte, J.-F.; Ramos, S.; Rapatsky, V.; Reicherz, G.; Richter, A.; Robinet, F.; Rocco, E.; Rondio, E.; Ryabchikov, D.I.; Samoylenko, V.D.; Sandacz, A.; Santos, H.; Sapozhnikov, M.G.; Sarkar, S.; Savin, I.A.; Sbrizza, G.; Schiavon, P.; Schill, C.; Schluter, T.; Schmitt, L.; Schopferer, S.; Schroder, W.; Shevchenko, O.Yu.; Siebert, H.-W.; Silva, L.; Sinha, L.; Sissakian, A.N.; Slunecka, M.; Smirnov, G.I.; Sosio, S.; Sozzi, F.; Srnka, A.; Stolarski, M.; Sulc, M.; Sulej, R.; Takekawa, S.; Tessaro, S.; Tessarotto, F.; Teufel, A.; Tkatchev, L.G.; Uhl, S.; Uman, I.; Virius, M.; Vlassov, N.V.; Vossen, A.; Weitzel, Q.; Windmolders, R.; Wislicki, W.; Wollny, H.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zhao, J.; Zhuravlev, N.; Zvyagin, A.

    2010-01-01

    The Collins and Sivers asymmetries for charged hadrons produced in deeply inelastic scattering on transversely polarised protons have been extracted from the data collected in 2007 with the CERN SPS muon beam tuned at 160 GeV/c. At large values of the Bjorken x variable non-zero Collins asymmetries are observed both for positive and negative hadrons while the Sivers asymmetry for positive hadrons is slightly positive over almost all the measured x range. These results nicely support the present theoretical interpretation of these asymmetries, in terms of leading-twist quark distribution and fragmentation functions.

  8. Spontaneous tension haemopneumothorax

    OpenAIRE

    Patterson, Benjamin Oliver; Itam, Sarah; Probst, Fey

    2008-01-01

    Abstract We present a patient with sudden onset progressive shortness of breath and no history of trauma, who rapidly became haemodynamically compromised with a pneumothorax and pleural effusion seen on chest radiograph. He was treated for spontaneous tension pneumothorax but this was soon revealed to be a tension haemopneumothorax. He underwent urgent thoracotomy after persistent bleeding to explore an apical vascular abnormality seen on CT scanning. To our knowledge this is the first such c...

  9. Spontaneous spinal epidural abscess.

    LENUS (Irish Health Repository)

    Ellanti, P

    2011-10-01

    Spinal epidural abscess is an uncommon entity, the frequency of which is increasing. They occur spontaneously or as a complication of intervention. The classical triad of fever, back pain and neurological symptoms are not always present. High index of suspicion is key to diagnosis. Any delay in diagnosis and treatment can have significant neurological consequences. We present the case of a previously well man with a one month history of back pain resulting from an epidural abscess.

  10. Reconstruction of 3d grain boundaries from rock thin sections, using polarised light

    Science.gov (United States)

    Markus Hammes, Daniel; Peternell, Mark

    2016-04-01

    Grain boundaries affect the physical and chemical properties of polycrystalline materials significantly by initiating reactions and collecting impurities (Birchenall, 1959), and play an essential role in recrystallization (Doherty et al. 1997). In particular, the shape and crystallographic orientation of grain boundaries reveal the deformation and annealing history of rocks (Kruhl and Peternell 2002, Kuntcheva et al. 2006). However, there is a lack of non-destructive and easy-to-use computer supported methods to determine grain boundary geometries in 3D. The only available instrument using optical light to measure grain boundary angles is still the polarising microscope with attached universal stage; operated manually and time-consuming in use. Here we present a new approach to determine 3d grain boundary orientations from 2D rock thin sections. The data is recorded by using an automatic fabric analyser microscope (Peternell et al., 2010). Due to its unique arrangement of 9 light directions the highest birefringence colour due to each light direction and crystal orientation (retardation) can be determined at each pixel in the field of view. Retardation profiles across grain boundaries enable the calculation of grain boundary angle and direction. The data for all positions separating the grains are combined and further processed. In combination with the lateral position of the grain boundary, acquired using the FAME software (Hammes and Peternell, in review), the data is used to reconstruct a 3d grain boundary model. The processing of data is almost fully automatic by using MATLAB®. Only minor manual input is required. The applicability was demonstrated on quartzite samples, but the method is not solely restricted on quartz grains and other birefringent polycrystalline materials could be used instead. References: Birchenall, C.E., 1959: Physical Metallurgy. McGraw-Hill, New York. Doherty, R.D., Hughes, D.A., Humphreys, F.J., Jonas, J.J., Juul Jensen, D., Kassner, M

  11. Spontaneous baryogenesis in supersymmetric models

    International Nuclear Information System (INIS)

    Abel, S.A.; Cottingham, W.N.; Whittingham, I.B.

    1993-01-01

    In this paper we extent the results of previous work on spontaneous baryogenesis to general models involving charge-parity (CP) violation in the Higgs sector. We show how to deal with Chern-Simons terms appearing in the effective potential arising from phase changes in the vacuum expectation values of the Higgs fields. In particular, this enables us to apply this mechanism to general supersymmetric models including the minimal supersymmetric standard model, and the extended model with a gauge singlet. A comparison is made between this approach, and that in which one solves the equations of motion for Higgs winding modes. As anticipated in earlier work, the effect of the latter approach is found to be small. (Author)

  12. A morphological study of the sulfurisation of digenite to covellite using reflected polarised light microscopy

    DEFF Research Database (Denmark)

    Rask Møller Frøkiær, Heidi; Warner, Terence E.

    2017-01-01

    A series of copper rods were reacted with sulfur vapour in evacuated glass ampoules at ∼445 °C. Product materials were characterised by powder X-ray diffraction and reflected polarised light microscopy. Copper sulfurised rapidly to digenite, γ-Cu2-xS, under these conditions, whereas the subsequen...... of the covellite structure. Sulfurising a coil of copper wire at ∼445 °C is an effective method for synthesising covellite.......A series of copper rods were reacted with sulfur vapour in evacuated glass ampoules at ∼445 °C. Product materials were characterised by powder X-ray diffraction and reflected polarised light microscopy. Copper sulfurised rapidly to digenite, γ-Cu2-xS, under these conditions, whereas the subsequent...... − besides being a p-type metal − is ionically conducting at 445 °C, although considerably less so than digenite. We infer that the growth of platy covellite crystals and their radial alignment in the primary CuS layer are a consequence of copper ion mobility being restricted to the basal plane...

  13. First measurement of the gluon polarisation in the nucleon using D mesons at COMPASS

    CERN Document Server

    von Hodenberg, Martin

    2005-01-01

    The complicated structure of the nucleon has been studied with great success in deep-inelastic lepton-nucleon scattering (DIS) experiments at CERN, SLAC and DESY. As a result the unpolarised structure functions have been measured accurately over a wide kinematic range. From these measurements it is possible to determine the gluon density in the nucleon with good accuracy via a so-called QCD fit. In the case of the spin structure of the nucleon the situation is different. Even after decades of experimental and theoretical efforts it remains to be understood how the spin of the nucleon of 1/2 in units of h-bar is to be accounted for in terms of contributions from the quarks and gluons inside the nucleon. Of particular interest is the question whether the polarised gluon density can explain the unexpected smallness of the quark contribution to the nucleon spin. The QCD fit, which worked well in the unpolarised case, yields a polarised gluon density Delta G which is only badly constrained. This is due to the fact...

  14. Inclusive Deep Inelastic Scattering at High Q2 with Longitudinally Polarised Lepton Beams at HERA

    CERN Document Server

    Aaron, F.D.; Andreev, V.; Backovic, S.; Baghdasaryan, A.; Baghdasaryan, S.; Barrelet, E.; Bartel, W.; Begzsuren, K.; Belousov, A.; Belov, P.; Bizot, J.C.; Boudry, V.; Bozovic-Jelisavcic, I.; Bracinik, J.; Brandt, G.; Brinkmann, M.; Brisson, V.; Britzger, D.; Bruncko, D.; Bunyatyan, A.; Bylinkin, A.; Bystritskaya, L.; Campbell, A.J.; Cantun Avila, K.B.; Ceccopieri, F.; Cerny, K.; Cerny, V.; Chekelian, V.; Contreras, J.G.; Coughlan, J.A.; Cvach, J.; Dainton, J.B.; Daum, K.; Delcourt, B.; Delvax, J.; De Wolf, E.A.; Diaconu, C.; Dobre, M.; Dodonov, V.; Dossanov, A.; Dubak, A.; Eckerlin, G.; Egli, S.; Eliseev, A.; Elsen, E.; Favart, L.; Fedotov, A.; Felst, R.; Feltesse, J.; Ferencei, J.; Fischer, D.J.; Fleischer, M.; Fomenko, A.; Gabathuler, E.; Gayler, J.; Ghazaryan, S.; Glazov, A.; Goerlich, L.; Gogitidze, N.; Gouzevitch, M.; Grab, C.; Grebenyuk, A.; Greenshaw, T.; Grindhammer, G.; Habib, S.; Haidt, D.; Henderson, R.C.W.; Hennekemper, E.; Henschel, H.; Herbst, M.; Herrera, G.; Hildebrandt, M.; Hiller, K.H.; Hladky, J.; Hoffmann, D.; Horisberger, R.; Hreus, T.; Huber, F.; Jacquet, M.; Janssen, X.; Jonsson, L.; Jung, H.; Kapichine, M.; Kenyon, I.R.; Kiesling, C.; Klein, M.; Kleinwort, C.; Kogler, R.; Kostka, P.; Kramer, M.; Kretzschmar, J.; Kruger, K.; Landon, M.P.J.; Lange, W.; Lastovicka-Medin, G.; Laycock, P.; Lebedev, A.; Lendermann, V.; Levonian, S.; Li, G.; Lipka, K.; List, B.; List, J.; Lobodzinski, B.; Lopez-Fernandez, R.; Lubimov, V.; Malinovski, E.; Martyn, H.U.; Maxfield, S.J.; Mehta, A.; Meyer, A.B.; Meyer, H.; Meyer, J.; Mikocki, S.; Milcewicz-Mika, I.; Moreau, F.; Morozov, A.; Morris, J.V.; Muller, K.; Naumann, Th.; Newman, P.R.; Niebuhr, C.; Nikiforov, A.; Nikitin, D.; Nowak, G.; Nowak, K.; Olsson, J.E.; Ozerov, D.; Pahl, P.; Palichik, V.; Pandurovic, M.; Pascaud, C.; Patel, G.D.; Perez, E.; Petrukhin, A.; Picuric, I.; Pirumov, H.; Pitzl, D.; Placakyte, R.; Pokorny, B.; Polifka, R.; Povh, B.; Radescu, V.; Raicevic, N.; Ravdandorj, T.; Reimer, P.; Rizvi, E.; Robmann, P.; Roosen, R.; Rostovtsev, A.; Rotaru, M.; Ruiz Tabasco, J.E.; Rusakov, S.; Salek, D.; Sankey, D.P.C.; Sauter, M.; Sauvan, E.; Schmitt, S.; Schoeffel, L.; Schoning, A.; Schultz-Coulon, H.C.; Sefkow, F.; Shtarkov, L.N.; Shushkevich, S.; Sloan, T.; Soloviev, Y.; Sopicki, P.; South, D.; Spaskov, V.; Specka, A.; Staykova, Z.; Steder, M.; Stella, B.; Stoicea, G.; Straumann, U.; Sykora, T.; Thompson, P.D.; Tran, T.H.; Traynor, D.; Truol, P.; Tsakov, I.; Tseepeldorj, B.; Turnau, J.; Valkarova, A.; Vallee, C.; Van Mechelen, P.; Vazdik, Y.; Wegener, D.; Wunsch, E.; Zacek, J.; Zalesak, J.; Zhang, Z.; Zhokin, A.; Zlebcik, R.; Zohrabyan, H.; Zomer, F.

    2012-01-01

    Inclusive e\\pmp single and double differential cross sections for neutral and charged current deep inelastic scattering processes are measured with the H1 detector at HERA. The data were taken at a centre-of-mass energy of \\surds = 319GeV with a total integrated luminosity of 333.7 pb-1 shared between two lepton beam charges and two longitudinal lepton polarisation modes. The differential cross sections are measured in the range of negative fourmomentum transfer squared, Q2, between 60 and 50 000GeV2, and Bjorken x between 0.0008 and 0.65. The measurements are combined with earlier published unpolarised H1 data to improve statistical precision and used to determine the structure function xF_3^gammaZ. A measurement of the neutral current parity violating structure function F_2^gammaZ is presented for the first time. The polarisation dependence of the charged current total cross section is also measured. The new measurements are well described by a next-to-leading order QCD fit based on all published H1 inclusi...

  15. Simulations of the polarisation-dependent Raman intensity of β-carotene in photosystem II crystals

    International Nuclear Information System (INIS)

    Brose, K.; Zouni, A.; Müh, F.; Mroginski, M.A.; Maultzsch, J.

    2013-01-01

    Highlights: • First polarisation-dependent Raman spectroscopy on photosystem II crystals. • Orientation-dependent Raman intensity simulations for di- and monomeric crystals. • Simulations account for all β-carotenes (β-Car) in the unit cell for the first time. • Prediction for identificationy of the β-Car cation in side-path electron transport. - Abstract: In order to clarify possibilities to identify the β-carotene (β-Car) radicals in secondary electron transfer (ET) reactions in the photosystem II core complex (PSIIcc), Raman intensities of all 96 β-Car cofactors in the unit cell of PSIIcc-dimer crystals as a function of polarisation and crystal orientation were simulated based on the 2.9 Å resolution structure. The Raman-active symmetry A g in the C 2h group is assigned to the β-Car modes ν 66 and ν 67 . Simulations are in agreement with experiment for off-resonant excitation at 1064 nm. Resonant measurements at 476 and 532 nm excitation can not be explained, which is attributed to mode mixing in the excited state and the existence of different spectral pools. The identity of the β-Car oxidised in secondary ET can not be resolved by Raman measurements on PSIIcc-dimer crystals. Additional simulations show that similar measurements on PSIIcc-monomer crystals could provide a possible route to solve this issue

  16. Simulations of the polarisation-dependent Raman intensity of β-carotene in photosystem II crystals

    Energy Technology Data Exchange (ETDEWEB)

    Brose, K., E-mail: katharina.brose@gmx.net [Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin (Germany); Zouni, A. [Institut für Chemie, Max-Volmer-Laboratorium, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin (Germany); Müh, F. [Institut für Theoretische Physik, Johannes Kepler Universität Linz, Altenberger Straße 69, 4040 Linz (Austria); Mroginski, M.A. [Institut für Chemie, Max-Volmer-Laboratorium, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin (Germany); Maultzsch, J. [Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstraße 36, 10623 Berlin (Germany)

    2013-06-03

    Highlights: • First polarisation-dependent Raman spectroscopy on photosystem II crystals. • Orientation-dependent Raman intensity simulations for di- and monomeric crystals. • Simulations account for all β-carotenes (β-Car) in the unit cell for the first time. • Prediction for identificationy of the β-Car cation in side-path electron transport. - Abstract: In order to clarify possibilities to identify the β-carotene (β-Car) radicals in secondary electron transfer (ET) reactions in the photosystem II core complex (PSIIcc), Raman intensities of all 96 β-Car cofactors in the unit cell of PSIIcc-dimer crystals as a function of polarisation and crystal orientation were simulated based on the 2.9 Å resolution structure. The Raman-active symmetry A{sub g} in the C{sub 2h} group is assigned to the β-Car modes ν{sub 66} and ν{sub 67}. Simulations are in agreement with experiment for off-resonant excitation at 1064 nm. Resonant measurements at 476 and 532 nm excitation can not be explained, which is attributed to mode mixing in the excited state and the existence of different spectral pools. The identity of the β-Car oxidised in secondary ET can not be resolved by Raman measurements on PSIIcc-dimer crystals. Additional simulations show that similar measurements on PSIIcc-monomer crystals could provide a possible route to solve this issue.

  17. Propagation of TE and TM polarised light through smoothed sixty degree bends in planar photonic crystal waveguides

    DEFF Research Database (Denmark)

    Frandsen, Lars Hagedorn; Borel, Peter Ingo; Thorhauge, Morten

    2003-01-01

    In this paper, bends in planar PCWs are investigated by introducing two smoothed 60° bends each having one hole. The PCWs are defined by leaving out single rows of holes. In and out coupling of light to the PCWs is obtained utilising tapered ridge waveguides. Transmission spectra are recorded for...... for both the TE and TM polarisation with an optical spectrum analyser by using two LED sources centred at 1330 nm and 1550 nm. The 3D FDTD simulations successfully explain the observed bend losses both for the TE and TM polarisations....

  18. Measurements of magnetic fields generated in underdense plasmas by intense lasers

    International Nuclear Information System (INIS)

    Najmudin, Z.; Walton, B. R.; Mangles, S. P. D.; Dangor, A. E.; Krushelnick, K.; Fritzler, S.; Malka, V.; Faure, J.; Tatarakis, M.

    2006-01-01

    Measurements have been made of the magnetic field generated by the passage of high intensity short laser pulses through underdense plasmas. For a 30 fs, 1 J, 800 nm linearly-polarised laser pulse, an azimuthal magnetic field is observed at a radial extent of approximately 200 μm. The field is found to exceed 2.8 MG. For a 1 ps, 40 J, 1054 nm circularly-polarised laser pulse, a solenoidal field is observed that can exceed 7 MG. This solenoidal field is absent with linear polarised light, and hence can be considered as an Inverse Faraday effect. Both types of field are found to decay on the picosecond timescale. For both the azimuthal and solenoidal fields produced by such intense lasers, the production of energetic electrons by the interaction is thought to be vital for magnetic field generation

  19. Study of magnetic thin films by polarized neutron reflectivity. Off-specular diffusion on periodical structures; Etude de couches minces magnetiques par reflectivite de neutrons polarises. Diffusion non speculaire sur des structures periodiques

    Energy Technology Data Exchange (ETDEWEB)

    Ott, F

    1998-11-26

    Theoretical (Zeeman energy effects) and experimental (beam polarisation problems) progress have been made in the understanding of polarized neutron reflectivity with polarisation analysis. It has been shown that modelization and numerical simulations makes it possible to avoid to have to systematically measure a full set of reflectivity curves for each field and temperature condition. It has been possible to determine a magnetic profile as a function of the field in a magnetic bilayer system by using only a few points in the reciprocal space. This technique allows to considerable reduce the experiment time. In single nickel layer systems, we have shown that it is possible to induce magnetic rotation inhomogeneities when these systems are subjects to deformation strains. The effect are related to magneto-elastic constants gradients. In trilayer systems, with a ME constant modulation, we have been able to induce large magnetic rotation gradients. A new magneto-optic technique to measure the magnetization direction without rotating the magnetic field has been developed. The field of neutron reflectivity has been extended to off-specular studies. It has been possible to account quantitatively of the off-specular diffusion on 2-D model systems (prepared by optical lithography). This new technique should make it possible in the future to determine magnetic structures with a in-depth as well as lateral resolution. (author)

  20. Spontaneously broken mass

    International Nuclear Information System (INIS)

    Endlich, Solomon; Nicolis, Alberto; Penco, Riccardo

    2015-01-01

    The Galilei group involves mass as a central charge. We show that the associated superselection rule is incompatible with the observed phenomenology of superfluid helium 4: this is recovered only under the assumption that mass is spontaneously broken. This remark is somewhat immaterial for the real world, where the correct space-time symmetries are encoded by the Poincaré group, which has no central charge. Yet it provides an explicit example of how superselection rules can be experimentally tested. We elaborate on what conditions must be met for our ideas to be generalizable to the relativistic case of the integer/half-integer angular momentum superselection rule.

  1. Spontaneous Tumor Lysis Syndrome

    Directory of Open Access Journals (Sweden)

    Alicia C. Weeks MD

    2015-08-01

    Full Text Available Tumor lysis syndrome (TLS is a known complication of malignancy and its treatment. The incidence varies on malignancy type, but is most common with hematologic neoplasms during cytotoxic treatment. Spontaneous TLS is thought to be rare. This case study is of a 62-year-old female admitted with multisystem organ failure, with subsequent diagnosis of aggressive B cell lymphoma. On admission, laboratory abnormalities included renal failure, elevated uric acid (20.7 mg/dL, and 3+ amorphous urates on urinalysis. Oliguric renal failure persisted despite aggressive hydration and diuretic use, requiring initiation of hemodialysis prior to chemotherapy. Antihyperuricemic therapy and hemodialysis were used to resolve hyperuricemia. However, due to multisystem organ dysfunction syndrome with extremely poor prognosis, the patient ultimately expired in the setting of a terminal ventilator wean. Although our patient did not meet current TLS criteria, she required hemodialysis due to uric acid nephropathy, a complication of TLS. This poses the clinical question of whether adequate diagnostic criteria exist for spontaneous TLS and if the lack of currently accepted guidelines has resulted in the underestimation of its incidence. Allopurinol and rasburicase are commonly used for prevention and treatment of TLS. Although both drugs decrease uric acid levels, allopurinol mechanistically prevents formation of the substrate rasburicase acts to solubilize. These drugs were administered together in our patient, although no established guidelines recommend combined use. This raises the clinical question of whether combined therapy is truly beneficial or, conversely, detrimental to patient outcomes.

  2. Spontaneous intracranial hypotension

    International Nuclear Information System (INIS)

    Cardwell, C.; Cox, I.; Baldey, A.

    2002-01-01

    Full text: A 49-year old female presented with severe postural headache with no history of trauma. A Computed Tomography (CT) study of the brain demonstrated abnormal meningeal enhancement raising the possibility of leptomeningeal metastases. The patient was then referred to Magnetic Resonance Imaging (MRI) which demonstrated diffuse smooth dural enhancement with ancillary findings characteristic of spontaneous intracranial hypotension. The patient was then referred to Nuclear Medicine to confirm the diagnosis and localise the presumed leak 400MBq of 99mTc DTPA was injected via lumbar puncture into the L3-L4 subarachnoid space Posterior images of the spine were taken with a GE XRT single head gamma camera at 1 and 4 hours post administration of radionuclide. Images demonstrated abnormal early arrival of radionuclide in the kidneys and bladder at 1 hour and abnormal leak of tracer was demonstrate at the level of the first thoracic vertebra on the right side at 4 hours. This confirmed CSF leak at this level. Consequently the patient underwent a blood patch and her symptoms resolved. Spontaneous Intracranial Hypotension is a syndrome often unrecognised presenting with symptoms including severe postural headache neck stiffness nausea vomiting tinnitus and vertigo. The diagnosis is frequently suspected from findings on MRI, but Nuclear Medicine CSF imaging provides a readily available and cost effective method for confirming the diagnosis, and for making the diagnosis in patients who are unsuitable for or do not have access to MRI. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc

  3. Spontaneous intracranial hypotension

    Energy Technology Data Exchange (ETDEWEB)

    Cardwell, C; Cox, I; Baldey, A [St. F.X. Cabrini Hospital, VIC (Australia). Departments of Nuclear Medicine and Magnetic Resonance Imaging

    2002-07-01

    Full text: A 49-year old female presented with severe postural headache with no history of trauma. A Computed Tomography (CT) study of the brain demonstrated abnormal meningeal enhancement raising the possibility of leptomeningeal metastases. The patient was then referred to Magnetic Resonance Imaging (MRI) which demonstrated diffuse smooth dural enhancement with ancillary findings characteristic of spontaneous intracranial hypotension. The patient was then referred to Nuclear Medicine to confirm the diagnosis and localise the presumed leak 400MBq of 99mTc DTPA was injected via lumbar puncture into the L3-L4 subarachnoid space Posterior images of the spine were taken with a GE XRT single head gamma camera at 1 and 4 hours post administration of radionuclide. Images demonstrated abnormal early arrival of radionuclide in the kidneys and bladder at 1 hour and abnormal leak of tracer was demonstrate at the level of the first thoracic vertebra on the right side at 4 hours. This confirmed CSF leak at this level. Consequently the patient underwent a blood patch and her symptoms resolved. Spontaneous Intracranial Hypotension is a syndrome often unrecognised presenting with symptoms including severe postural headache neck stiffness nausea vomiting tinnitus and vertigo. The diagnosis is frequently suspected from findings on MRI, but Nuclear Medicine CSF imaging provides a readily available and cost effective method for confirming the diagnosis, and for making the diagnosis in patients who are unsuitable for or do not have access to MRI. Copyright (2002) The Australian and New Zealand Society of Nuclear Medicine Inc.

  4. Measurement of high-Q2 deep inelastic scattering cross sections with a longitudinally polarised positron beam at HERA

    NARCIS (Netherlands)

    Chekanov, S.; Kooijman, P.

    2006-01-01

    The cross sections for charged and neutral current deep inelastic scattering in e+p collisions with a longitudinally polarised positron beam have been measured using the ZEUS detector at HERA. The results, based on data corresponding to an integrated luminosity of 23.8 pb−1 at , are given for both

  5. Comparison of polarisation curves and chronoamperometry experiments of titanium with and without ultrasonic vibrations of the electrolyte

    Directory of Open Access Journals (Sweden)

    Rebecca Leese

    2016-03-01

    Full Text Available Ultrasonic vibrations were applied to the electrolyte in polarisation curve and chronoamperometry to observe the effect of anodic dissolution with the aim to apply knowledge to electrochemical machining. The application of the ultrasonic vibrations to the electrolyte allowed the dissolution potential to be lowered considerably and the machining rates were increased.

  6. The polarised photon g1γ sum rule at the linear collider and high luminosity B factories

    International Nuclear Information System (INIS)

    Shore, G.M.

    2005-01-01

    The sum rule for the first moment of the polarised (virtual) photon structure function g 1 γ (x,Q 2 ;K 2 ) is revisited in the light of proposals for future e + e - colliders. The sum rule exhibits an array of phenomena characteristic of QCD: for real photons (K 2 =0) electromagnetic gauge invariance constrains the first moment to vanish; the limit for asymptotic photon virtuality (m ρ 2 -bar K 2 -bar Q 2 ) is governed by the electromagnetic U A (1) axial anomaly and the approach to asymptopia by the gluonic anomaly; for intermediate values of K 2 , it reflects the realisation of chiral symmetry and is determined by the off-shell radiative couplings of the pseudoscalar mesons; finally, like many polarisation phenomena in QCD, the first moment of g 1 γ involves the gluon topological susceptibility. In this paper, we review the original sum rule proposed by Narison, Shore and Veneziano and extend the relation with pseudoscalar mesons. The possibility of measuring the sum rule in future polarised e + e - colliders is then considered in detail, focusing on the International Linear Collider (ILC) and high luminosity B factories. We conclude that all the above features of the sum rule should be accessible at a polarised collider with the characteristics of SuperKEKB

  7. Measurement of 1.7–74 MeV polarised γ rays with the HARPO TPC

    Energy Technology Data Exchange (ETDEWEB)

    Geerebaert, Y., E-mail: yannick.geerebaert@polytechnique.fr [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Gros, Ph., E-mail: philippe.gros@llr.in2p3.fr [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Amano, S. [LASTI, University of Hyôgo (Japan); Attié, D. [CEA, Irfu, CEA-Saclay (France); Bernard, D.; Bruel, P. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Calvet, D.; Colas, P. [CEA, Irfu, CEA-Saclay (France); Daté, S. [JASRI/SPring8 (Japan); Delbart, A. [CEA, Irfu, CEA-Saclay (France); Frotin, M.; Giebels, B. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Götz, D. [AIM, CEA/DSM-CNRS – Université Paris Diderot (France); IRFU/Service d' Astrophysique, CEA-Saclay (France); Hashimoto, S. [LASTI, University of Hyôgo (Japan); Horan, D. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Kotaka, T. [LASTI, University of Hyôgo (Japan); Louzir, M. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Minamiyama, Y.; Miyamoto, S. [LASTI, University of Hyôgo (Japan); Ohkuma, H. [JASRI/SPring8 (Japan); and others

    2017-02-11

    Current γ-ray telescopes based on photon conversions to electron-positron pairs, such as Fermi, use tungsten converters. They suffer of limited angular resolution at low energies, and their sensitivity drops below 1 GeV. The low multiple scattering in a gaseous detector gives access to higher angular resolution in the MeV–GeV range, and to the linear polarisation of the photons through the azimuthal angle of the electron-positron pair. HARPO is an R&D programme to characterise the operation of a TPC (Time Projection Chamber) as a high angular-resolution and sensitivity telescope and polarimeter for γ rays from cosmic sources. It represents a first step towards a future space instrument. A 30 cm cubic TPC demonstrator was built, and filled with 2 bar argon-based gas. It was put in a polarised γ-ray beam at the NewSUBARU accelerator in Japan in November 2014. Data were taken at different photon energies from 1.7 MeV to 74 MeV, and with different polarisation configurations. The electronics setup is described, with an emphasis on the trigger system. The event reconstruction algorithm is quickly described, and preliminary measurements of the polarisation of 11 MeV photons are shown.

  8. Minute splitting of magnetic excitations in CsFeCl{sub 3} due to dipolar interaction observed by polarised neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Dorner, B [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France); Baehr, M [HMI, Berlin (Germany); Petitgrand, D [Laboratoire Leon Brillouin (LLB) - Centre d` Etudes de Saclay, 91 - Gif-sur-Yvette (France)

    1997-04-01

    Using inelastic neutron scattering with polarisation analysis it was possible, for the first time, to observe simultaneously the two magnetic modes split due to dipolar interaction. This would not have been possible with energy resolution only. An analysis of eigenvectors was also performed. (author). 4 refs.

  9. Pole plus cut model and recent polarisation results for the reaction. pi. /sup -/p. -->. pi. /sup 0/n

    Energy Technology Data Exchange (ETDEWEB)

    Fazal-e-Aleem; Saleem, M. (University of the Punjab, Lahore (Pakistan). Centre for High Energy Physics); Rafique, M. (University of the Punjab, Lahore (Pakistan). Dept. of Mathematics)

    1984-10-01

    A pole plus cut model has been used to fit simultaneously the data on dsigma/dt, P(t) and ..delta..sigma for the reaction ..pi../sup -/p ..-->.. ..pi../sup 0/n at high energies; the most recent measurements of polarisation are included in the fit.

  10. Increase in data capacity utilising dimensions of wavelength, space, time, polarisation and multilevel modulation using a single laser

    DEFF Research Database (Denmark)

    Clausen, Anders; Hu, Hao; Ye, Feihong

    2015-01-01

    Increasing the capacity of optical networks while have the objective of lowering the total consumed energy per bit is challenging. By exploiting several dimensions, i.e. wavelength, space, time, polarisation and multilevel modulation simultaneously, a single laser can offer formidable capacity pe...... performance with potentially reduced energy consumption per bit. Up to 43 Tbit/s has been demonstrated....

  11. Self energy QED: Multipole spontaneous emission

    International Nuclear Information System (INIS)

    Salamin, Y.I.

    1990-08-01

    Within the context of Barut's self-field approach, we write the exact expression of the spontaneous atomic decay rate (Phys. Rev. A37, 2284 (1988)), in the long wavelength approximation, in terms of electric- and magnetic-like multipole contributions which are related to the matrix elements of the transition charge and current distributions of the relativistic electron. A number of features of these expressions are discussed and their generalization to interacting composite systems is also pointed out. (author). 8 refs

  12. Hierarchy stability for spontaneously broken theories

    Energy Technology Data Exchange (ETDEWEB)

    Galvan, J B; Perez-Mercader, J; Sanchez, F J

    1987-04-16

    By using Weisberger's method for the integration of heavy degrees of freedom in multiscale theories, we show that tree level hierarchies are not destabilized byquantum corrections in a two-scale, two scalar field theory model where the heavy sector undergoes spontaneous symmetry breaking. We see explicitly the role played by the one-loop heavy log corrections to the effective parameters in maintaining the original tree level hierarchy and in keeping the theory free of hierarchy problems.

  13. Hierarchy stability for spontaneously broken theories

    International Nuclear Information System (INIS)

    Galvan, J.B.; Perez-Mercader, J.; Sanchez, F.J.

    1987-01-01

    By using Weisberger's method for the integration of heavy degrees of freedom in multiscale theories, we show that tree level hierarchies are not destabilized byquantum corrections in a two-scale, two scalar field theory model where the heavy sector undergoes spontaneous symmetry breaking. We see explicitly the role played by the one-loop heavy log corrections to the effective parameters in maintaining the original tree level hierarchy and in keeping the theory free of hierarchy problems. (orig.)

  14. Cosmological aspects of spontaneous baryogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Simone, Andrea De; Kobayashi, Takeshi [SISSA,Via Bonomea 265, 34136 Trieste (Italy); INFN, Sezione di Trieste,Via Bonomea 265, 34136 Trieste (Italy)

    2016-08-24

    We investigate cosmological aspects of spontaneous baryogenesis driven by a scalar field, and present general constraints that are independent of the particle physics model. The relevant constraints are obtained by studying the backreaction of the produced baryons on the scalar field, the cosmological expansion history after baryogenesis, and the baryon isocurvature perturbations. We show that cosmological considerations alone provide powerful constraints, especially for the minimal scenario with a quadratic scalar potential. Intriguingly, we find that for a given inflation scale, the other parameters including the reheat temperature, decoupling temperature of the baryon violating interactions, and the mass and decay constant of the scalar are restricted to lie within ranges of at most a few orders of magnitude. We also discuss possible extensions to the minimal setup, and propose two ideas for evading constraints on isocurvature perturbations: one is to suppress the baryon isocurvature with nonquadratic scalar potentials, another is to compensate the baryon isocurvature with cold dark matter isocurvature by making the scalar survive until the present.

  15. Multi-pulse operation of a dissipative soliton fibre laser based on nonlinear polarisation rotation

    Energy Technology Data Exchange (ETDEWEB)

    Yu, H L; Wang, X L; Zhou, P; Chen, J B [College of Optoelectronics Science and Engineering, National University of Defense Technology, Changsha, Hunan, 410073 (China)

    2016-03-31

    We report an experimental observation of multiple dissipative soliton (DS) operation states in an all-normal-dispersion passively mode-locked Yb-doped fibre laser, including DS bound and oscillating states. In the bound state, multiple DSs up to 11 can coexist in the cavity. In the oscillating state, the DSs' movements are not purely random and three typical states are generalised and illustrated. A single-pulse mode-locked state is established at a high pump power by carefully adjusting the polarisation controllers. The broad spectrum indicates that it may be noise-like pulses, which can serve as a pump to generate a supercontinuum. (control of laser radiation parameters)

  16. Effect of radioactive chromate on the corrosion and polarisation of mild steel in sodium chloride solution

    International Nuclear Information System (INIS)

    Subramanyan, N.; Ramakrishnaiah, K.; Iyer, S.V.; Kapali, V.

    1980-01-01

    Corrosion tests of mild steel in 0.01% sodium chloride containing radioactive chromate and non-radioactive chromate have been carried out. It has been observed that the labelled sodium chromate has a deleterious effect on the inhibitive action of non-radioactive chromate. The effect of radioactive chromate on the potentiostatic polarization of m.s. in sodium chloride solution containing non-radioactive sodium chromate has also been studied. It is observed that both the cathodic and the anodic polarisation of the metal is diminished in the presence of radioactive chromate. The behaviour of the system in the presence of radioactive chromate is attributed both to the action of depolarisers produced by radiolysis of water and to the effect of gamma radiation on the metal. (author)

  17. Quantum coherence, top transverse polarisation and the Tevatron asymmetry $A_{FB}^\\ell$

    CERN Document Server

    Aguilar-Saavedra, J A

    2014-01-01

    We revisit the relation between the asymmetries $A_{FB}$ and $A_{FB}^\\ell$ in $t \\bar t$ production at the Tevatron, using as new physics benchmark a colour octet. We find that $A_{FB}^\\ell$ receives large contributions from the interference between $\\lambda = \\pm 1/2$ top helicity states, which has been ignored in some of the previous literature on the subject. The omission of these contributions results in a severe underestimation of the asymmetry, around $1/2$ and $1/50$ of the true value for right-handed and left-handed top couplings to the octet, respectively. Interference effects are closely related to a $\\mathcal{O}(1)$ transverse top polarisation, as yet not considered in this context.

  18. A new measurement of the Collins and Sivers asymmetries on a transversely polarised deuteron target

    CERN Document Server

    Ageev, E.S.; Alexandrov, Yu.; Alexeev, G.D.; Alexeev, M.; Amoroso, A.; Badelek, B.; Balestra, F.; Ball, J.; Barth, J.; Baum, G.; Becker, M.; Bedfer, Y.; Berglund, P.; Bernet, C.; Bertini, R.; Bettinelli, M.; Birsa, R.; Bisplinghoff, J.; Bordalo, P.; Bradamante, F.; Bressan, A.; Brona, G.; Burtin, E.; Bussa, M.P.; Bytchkov, V.N.; Chapiro, A.; Cicuttin, A.; Colantoni, M.; Colavita, A.A.; Costa, S.; Crespo, M.L.; dHose, N.; Dalla Torre, S.; Das, S.; Dasgupta, S.S.; De Masi, R.; Dedek, N.; Demchenko, D.; Denisov, O.Yu.; Dhara, L.; Diaz, V.; Dinkelbach, A.M.; Donskov, S.V.; Dorofeev, V.A.; Doshita, N.; Duic, V.; Dunnweber, W.; Efremov, A.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Falaleev, V.; Fauland, P.; Ferrero, A.; Ferrero, L.; Finger, M.; Jr., M.Finger; Fischer, H.; Franz, J.; Friedrich, J.M.; Frolov, V.; Fuchs, U.; Garfagnini, R.; Gautheron, F.; Gavrichtchouk, O.P.; Gerassimov, S.; Geyer, R.; Giorgi, M.; Gobbo, B.; Goertz, S.; Gorin, A.M.; Grajek, O.A.; Grasso, A.; Grube, B.; Guskov, A.; Haas, F.; Hannappel, J.; von Harrach, D.; Hasegawa, T.; Hedicke, S.; Heinsius, F.H.; Hermann, R.; He, C.; Hinterberger, F.; von Hodenberg, M.; Horikawa, N.; Horikawa, S.; Horn, I.; Ilgner, C.; Ioukaev, A.I.; Ishimoto, S.; Ivanchin, I.; Ivanov, O.; Iwata, T.; Jahn, R.; Janata, A.; Joosten, R.; Jouravlev, N.I.; Kabuss, E.; Kalinnikov, V.; Kang, D.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu.A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koblitz, S.; Koivuniemi, J.H.; Kolosov, V.N.; Komissarov, E.V.; Kondo, K.; Konigsmann, Kay; Konorov, I.; Konstantinov, V.F.; Korentchenko, A.S.; Korzenev, A.; Kotzinian, A.M.; Koutchinski, N.A.; Kouznetsov, O.; Kowalik, K.; Kramer, D.; Kravchuk, N.P.; Krivokhizhin, G.V.; Kroumchtein, Z.V.; Kubart, J.; Kuhn, R.; Kukhtin, V.; Kunne, F.; Kurek, K.; Ladygin, M.E.; Lamanna, M.; Goff, J.M.Le; Leberig, M.; Lednev, A.A.; Lehmann, A.; Lichtenstadt, J.; Liska, T.; Ludwig, I.; Maggiora, A.; Maggiora, M.; Magnon, A.; Mallot, G.K.; Marchand, C.; Marroncle, J.; Martin, A.; Marzec, J.; Masek, L.; Massmann, F.; Matsuda, T.; Matthia, D.; Maximov, A.N.; Meyer, W.; Mielech, A.; Mikhailov, Yu.V.; Moinester, M.A.; Nagel, T.; Nahle, O.; Nassalski, J.; Neliba, S.; Neyret, D.P.; Nikolaenko, V.I.; Nozdrin, A.A.; Obraztsov, V.F.; Olshevsky, A.G.; Ostrick, M.; Padee, A.; Pagano, P.; Panebianco, S.; Panzieri, D.; Paul, S.; Peshekhonov, D.V.; Peshekhonov, V.D.; Piragino, G.; Platchkov, S.; Platzer, K.; Pochodzalla, J.; Polak, J.; Polyakov, V.A.; Pontecorvo, G.; Popov, A.A.; Pretz, J.; Procureur, S.; Quintans, C.; Ramos, S.; Reicherz, G.; Richter, A.; Rondio, E.; Rozhdestvensky, A.M.; Ryabchikov, D.; Samoylenko, V.D.; Sandacz, A.; Santos, H.; Sapozhnikov, M.G.; Savin, Igor A.; Schiavon, P.; Schill, C.; Schmitt, L.; Schroeder, W.; Schoenmeier, P.; Seeharsch, D.; Seimetz, M.; Setter, D.; Shevchenko, O.Yu.; Siebert, H.-W.; Silva, L.; Sinha, L.; Sissakian, A.N.; Slunecka, M.; Smirnov, G.I.; Sozzi, F.; Srnka, A.; Stinzing, F.; Stolarski, M.; Sugonyaev, V.P.; Sulc, M.; Sulej, R.; Tchalishev, V.V.; Tessaro, S.; Tessarotto, F.; Teufel, A.; Tkatchev, L.G.; Toeda, T.; Trippel, S.; Venugopal, G.; Virius, M.; Vlassov, N.V.; Wagner, M.; Webb, R.; Weise, E.; Weitzel, Q.; Windmolders, R.; Wislicki, W.; Zanetti, A.M.; Zaremba, K.; Zavertyaev, M.; Zhao, J.; Ziegler, R.; Zvyagin, A.

    2007-01-01

    New high precision measurements of the Collins and Sivers asymmetries of charged hadrons produced in deep-inelastic scattering of muons on a transversely polarised 6LiD target are presented. The data were taken in 2003 and 2004 with the COMPASS spectrometer using the muon beam of the CERN SPS at 160 GeV/c. Both the Collins and Sivers asymmetries turn out to be compatible with zero, within the present statistical errors, which are more than a factor of 2 smaller than those of the published COMPASS results from the 2002 data. The final results from the 2002, 2003 and 2004 runs are compared with naive expectations and with existing model calculations

  19. Azimuthal asymmetries of charged hadrons produced by high-energy muons scattered off longitudinally polarised deuterons

    CERN Document Server

    Alekseev, M G; Alexandrov, Yu; Alexeev, G D; Amoroso, A; Austregesilo, A; Badełek, B; Balestra, F; Barth, J; Baum, G; Bedfer, Y; Bernhard, J; Bertini, R; Bettinelli, M; Birsa, R; Bisplinghoff, J; Bordalo, P; Bradamante, F; Bravar, A; Bressan, A; Brona, G; Burtin, E; Bussa, M P; Chaberny, D; Chiosso, M; Chung, S U; Cicuttin, A; Colantoni, M; Crespo, M L; Dalla Torre, S; Das, S; Dasgupta, S S; Denisov, O Yu; Dhara, L; Diaz, V; Donskov, S V; Doshita, N; Duic, V; Dünnweber, W; Efremov, A; El Alaoui, A; Eversheim, P D; Eyrich, W; Faessler, M; Ferrero, A; Filin, A; Finger, M; Finger, M Jr; Fischer, H; Franco, C; Friedrich, J M; Garfagnini, R; Gautheron, F; Gavrichtchouk, O P; Gazda, R; Gerassimov, S; Geyer, R; Giorgi, M; Gnesi, I; Gobbo, B; Goertz, S; Grabmüller, S; Grasso, A; Grube, B; Gushterski, R; Guskov, A; Haas, F; von Harrach, D; Hasegawa, T; Heinsius, F H; Herrmann, F; Heß, C; Hinterberger, F; Horikawa, N; Höppner, Ch; d’Hose, N; Ilgner, C; Ishimoto, S; Ivanov, O; Ivanshin, Yu; Iwata, T; Jahn, R; Jasinski, P; Jegou, G; Joosten, R; Kabuß, E; Kang, D; Ketzer, B; Khaustov, G V; Khokhlov, Yu A; Kisselev, Yu; Klein, F; Klimaszewski, K; Koblitz, S; Koivuniemi, J H; Kolosov, V N; Kondo, K; Königsmann, K; Konopka, R; Konorov, I; Konstantinov, V F; Korzenev, A; Kotzinian, A M; Kouznetsov, O; Kowalik, K; Krämer, M; Kral, A; Kroumchtein, Z V; Kuhn, R; Kunne, F; Kurek, K; Lauser, L; Le Goff, J M; Lednev, A A; Lehmann, A; Levorato, S; Lichtenstadt, J; Liska, T; Maggiora, A; Maggiora, M; Magnon, A; Mallot, G K; Mann, A; Marchand, C; Martin, A; Marzec, J; Massmann, F; Matsuda, T; Meyer, W; Michigami, T; Mikhailov, Yu V; Moinester, M A; Mutter, A; Nagaytsev, A; Nagel, T; Nassalski, J; Negrini, T; Nerling, F; Neubert, S; Neyret, D; Nikolaenko, V I; Nunes, A S; Olshevsky, A G; Ostrick, M; Padee, A; Panknin, R; Panzieri, D; Parsamyan, B; Paul, S; Pawlukiewicz-Kaminska, B; Perevalova, E; Pesaro, G; Peshekhonov, D V; Piragino, G; Platchkov, S; Pochodzalla, J; Polak, J; Polyakov, V A; Pontecorvo, G; Pretz, J; Quintans, C; Rajotte, J F; Ramos, S; Rapatsky, V; Reicherz, G; Richter, A; Robinet, F; Rocco, E; Rondio, E; Ryabchikov, D I; Samoylenko, V D; Sandacz, A; Santos, H; Sapozhnikov, M G; Sarkar, S; Savin, I A; Sbrizzai, G; Schiavon, P; Schill, C; Schlüter, T; Schmitt, L; Schopferer, S; Schröder, W; Shevchenko, O Yu; Siebert, H W; Silva, L; Sinha, L; Sissakian, A N; Slunecka, M; Smirnov, G I; Sosio, S; Sozzi, F; Srnka, A; Stolarski, M; Sulc, M; Sulej, R; Takekawa, S; Tessaro, S; Tessarotto, F; Teufel, A; Tkatchev, L G; Uhl, S; Uman, I; Virius, M; Vlassov, N V; Vossen, A; Weitzel, Q; Windmolders, R; Wislicki, W; Wollny, H; Zaremba, K; Zavertyaev, M; Zemlyanichkina, E; Ziembicki, M; Zhao, J; Zhuravlev, N; Zvyagin, A

    2010-01-01

    Azimuthal asymmetries in semi-inclusive production of positive (h^+) and negative hadrons (h^-) have been measured by scattering 160 GeV muons off longitudinally polarised deuterons at CERN. The asymmetries were decomposed in several terms according to their expected modulation in the azimuthal angle phi of the outgoing hadron. Each term receives contributions from one or several spin and transverse-momentum-dependent parton distribution and fragmentation functions. The amplitudes of all phi-modulation terms of the hadron asymmetries integrated over the kinematic variables are found to be consistent with zero within statistical errors, while the constant terms are nonzero and equal for h^+ and h^- within the statistical errors. The dependencies of the phi-modulated terms versus the Bjorken momentum fraction x, the hadron fractional momentum z, and the hadron transverse momentum p_h^T were studied. The x dependence of the constant terms for both positive and negative hadrons is in agreement with the longitudin...

  20. Tweeting on Catalonia’s Independence: The Dynamics of Political Discussion and Group Polarisation

    Directory of Open Access Journals (Sweden)

    Joan Balcells

    2016-12-01

    Full Text Available This article provides evidence in favour of social media serving as facilitators of public deliberation, in contrast with the hypothesis that emphasises the dominance of the “echo chamber” effect. It focuses on conversational interactions on Twitter between supporters from opposite sides in a potentially highly polarised political issue, i.e. the debate on the independence of Catalonia, which is used as a case study. Methodologically we rely on a random sample of communications on the Twitter reply network, involving for and against independence supporters. Remarkably, despite the tendency of forming homophilic networks, we find that communication across political lines is relatively frequent. Furthermore, heterogeneous conversations (where opposing sides are engaged in a dialogue tend to be significantly longer than homogenous ones (where all participants share the same view, which can be seen as a sign of genuine deliberation based on reasonably exchanging arguments between competing viewpoints.

  1. Spontaneous Intracranial Hypotension

    International Nuclear Information System (INIS)

    Joash, Dr.

    2015-01-01

    Epidemiology is not only rare but an important cause of new daily persistent headaches among young & middle age individuals. The Etiology & Pathogenesis is generally caused by spinal CSF leak. Precise cause remains largely unknown, underlying structural weakness of spinal meninges is suspected. There are several MR Signs of Intracranial Hypotension that include:- diffuse pachymeningeal (dural) enhancement; bilateral subdural, effusion/hematomas; Downward displacement of brain; enlargement of pituitary gland; Engorgement of dural venous sinuses; prominence of spinal epidural venous plexus and Venous sinus thrombosis & isolated cortical vein thrombosis. The sum of volumes of intracranial blood, CSF & cerebral tissue must remain constant in an intact cranium. Treatment in Many cases can be resolved spontaneously or by use Conservative approach that include bed rest, oral hydration, caffeine intake and use of abdominal binder. Imaging Modalities for Detection of CSF leakage include CT myelography, Radioisotope cisternography, MR myelography, MR imaging and Intrathecal Gd-enhanced MR

  2. Spontaneous soft tissue hematomas.

    Science.gov (United States)

    Dohan, A; Darnige, L; Sapoval, M; Pellerin, O

    2015-01-01

    Spontaneous muscle hematomas are a common and serious complication of anticoagulant treatment. The incidence of this event has increased along with the rise in the number of patients receiving anticoagulants. Radiological management is both diagnostic and interventional. Computed tomography angiography (CTA) is the main tool for the detection of hemorrhage to obtain a positive, topographic diagnosis and determine the severity. Detection of an active leak of contrast material during the arterial or venous phase is an indication for the use of arterial embolization. In addition, the interventional radiological procedure can be planned with CTA. Arterial embolization of the pedicles that are the source of the bleeding is an effective technique. The rate of technical and clinical success is 90% and 86%, respectively. Copyright © 2015 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

  3. Spontaneous wave packet reduction

    International Nuclear Information System (INIS)

    Ghirardi, G.C.

    1994-06-01

    There are taken into account the main conceptual difficulties met by standard quantum mechanics in dealing with physical processes involving macroscopic system. It is stressed how J.A.Wheeler's remarks and lucid analysis have been relevant to pinpoint and to bring to its extreme consequences the puzzling aspects of quantum phenomena. It is shown how the recently proposed models of spontaneous dynamical reduction represent a consistent way to overcome the conceptual difficulties of the standard theory. Obviously, many nontrivial problems remain open, the first and more relevant one being that of generalizing the model theories considered to the relativistic case. This is the challenge of the dynamical reduction program. 43 refs, 2 figs

  4. Market applications of Resistivity, Induced Polarisation, Magnetic Resonance and Electromagnetic methods for Groundwater Investigations, Mining Exploration, Environmental and Engineering Surveys

    Science.gov (United States)

    Bernard, J.

    2012-12-01

    The Manufacturers of geophysical instruments have been facing these past decades the fast evolution of the electronics and of the computer sciences. More automatisms have been introduced into the equipment and into the processing and interpretation software which may let believe that conducting geophysical surveys requires less understanding of the method and less experience than in the past. Hence some misunderstandings in the skills that are needed to make the geophysical results well integrated among the global information which the applied geologist needs to acquire to be successful in his applications. Globally, the demand in geophysical investigation goes towards more penetration depth, requiring more powerful transmitters, and towards a better resolution, requiring more data such as in 3D analysis. Budgets aspects strongly suggest a high efficiency in the field associated to high speed data processing. The innovation is required in all aspects of geophysics to fit with the market needs, including new technological (instruments, software) and methodological (methods, procedures, arrays) developments. The structures in charge of the geophysical work can be public organisations (institutes, ministries, geological surveys,…) or can come from the private sector (large companies, sub-contractors, consultants, …), each one of them getting their own constraints in the field work and in the processing and interpretation phases. In the applications concerning Groundwater investigations, Mining Exploration, Environmental and Engineering surveys, examples of data and their interpretation presently carried out all around the world will be presented for DC Resistivity (Vertical Electrical Sounding, 2D, 3D Resistivity Imaging, Resistivity Monitoring), Induced Polarisation (Time Domain 2D, 3D arrays for mining and environmental), Magnetic Resonance Sounding (direct detection and characterisation of groundwater) and Electromagnetic (multi-component and multi

  5. Stern-Gerlach effect without magnetic-field gradient

    International Nuclear Information System (INIS)

    Zimmer, O.; Felber, J.; Schaerpf, O.

    2001-01-01

    The Stern-Gerlach effect is the well-known spin-dependent splitting of a neutral particle beam by a magnetic-field gradient. Guided by the pseudomagnetic analogy, we performed a similar experiment where no magnetic-field gradient is involved. The effect is due to the spin-dependence of neutron scattering from polarised nuclei, i.e. caused by the strong interaction between neutrons and nuclei. The beam splitting is proportional to the nuclear polarisation and to the spin-dependent part of the neutron scattering length. Thus it can be used to measure one of both quantities. (orig.)

  6. Spontaneous decoherence of coupled harmonic oscillators confined in a ring

    Science.gov (United States)

    Gong, ZhiRui; Zhang, ZhenWei; Xu, DaZhi; Zhao, Nan; Sun, ChangPu

    2018-04-01

    We study the spontaneous decoherence of coupled harmonic oscillators confined in a ring container, where the nearest-neighbor harmonic potentials are taken into consideration. Without any external symmetry-breaking field or surrounding environment, the quantum superposition state prepared in the relative degrees of freedom gradually loses its quantum coherence spontaneously. This spontaneous decoherence is interpreted by the gauge couplings between the center-of-mass and the relative degrees of freedoms, which actually originate from the symmetries of the ring geometry and the corresponding nontrivial boundary conditions. In particular, such spontaneous decoherence does not occur at all at the thermodynamic limit because the nontrivial boundary conditions become the trivial Born-von Karman boundary conditions when the perimeter of the ring container tends to infinity. Our investigation shows that a thermal macroscopic object with certain symmetries has a chance for its quantum properties to degrade even without applying an external symmetry-breaking field or surrounding environment.

  7. Polarised photon and flavoured lepton quantum Boltzmann equations in the early universe; Polarisierte Photon- und geflavourte Lepton-Quantenboltzmanngleichungen im fruehen Universum

    Energy Technology Data Exchange (ETDEWEB)

    Fidler, Christian

    2011-12-16

    Polarisation and Nongaussianity are expected to play a central role in future studies of the cosmic microwave background radiation. Polarisation can be split into a divergence-like E-mode and a curl-like B-mode, of which the later can only be induced by primordial gravitational waves (tensor fluctuations of the metric) at leading order. Nongaussianity is not generated at first order and is directly proportional to the primordial Nongaussianity of inflation. Thus B-mode polarisation and Nongaussianity constrain inflation models directly. While E-mode polarisation has already been detected and is being observed with increasing precision, B-mode polarisation and Nongaussianity remains elusive. The absence of B-mode polarisation when the primordial fluctuations are purely scalar holds, however, only in linear perturbation theory. B-mode polarisation is also generated from scalar sources in second order, which may constitute an important background to the search for primordial gravitational waves. While such an effect would naturally be expected to be relevant at tensor-to-scalar ratios of order 10{sup -5}, which is the size of perturbations in the microwave background, only a full second order calculation can tell whether there are no enhancements. For Nongaussianity the situation is analogous: At second order intrinsic Nongaussianities are induced to the spectrum, which may be an important background to the primordial Nongaussianity. After the full second-order Boltzmann equations for the cosmological evolution of the polarised radiation distribution have become available, I focused on the novel sources to B-mode polarisation that appear in the second-order collision term, which have not been calculated before. In my PHD thesis I developed a numerical code, which solves the second order Boltzmann hierarchy and calculates the C{sub l}{sup BB}-spectrum.

  8. Spontaneous compactification to homogeneous spaces

    International Nuclear Information System (INIS)

    Mourao, J.M.

    1988-01-01

    The spontaneous compactification of extra dimensions to compact homogeneous spaces is studied. The methods developed within the framework of coset space dimensional reduction scheme and the most general form of invariant metrics are used to find solutions of spontaneous compactification equations

  9. Screening for spontaneous preterm birth

    NARCIS (Netherlands)

    van Os, M.A.; van Dam, A.J.E.M.

    2015-01-01

    Preterm birth is the most important cause of perinatal morbidity and mortality worldwide. In this thesis studies on spontaneous preterm birth are presented. The main objective was to investigate the predictive capacity of mid-trimester cervical length measurement for spontaneous preterm birth in a

  10. Simulation investigation of storage ring optical klystron spontaneous emission

    International Nuclear Information System (INIS)

    Xu Hongliang; Liu Jinying; He Duohui; Diao Caozheng; Jia Qika; Sun Baogen

    1998-01-01

    The spontaneous emission of TOK in Hefei storage ring was simulated with Monte Carlo method. Section one described the structure of the permanent magnet TOK and the magnet field of TOK. Section two simulated results, and simulated results illustrated how the energy spread and emittance of electron beam impose on the spectrum of spontaneous emission. And with help of simulated results, the causes of small modulation factor which was measured by experiment was discussed

  11. Spontaneous Pneumomediastinum: Hamman Syndrome

    Directory of Open Access Journals (Sweden)

    Tushank Chadha, BS

    2018-04-01

    significant fat stranding. The image also showed an intraluminal stent traversing the gastric antrum and gastric pylorus with no indication of obstruction. Circumferential mural thickening of the gastric antrum and body were consistent with the patient’s history of gastric adenocarcinoma. The shotty perigastric lymph nodes with associated fat stranding, along the greater curvature of the distal gastric body suggested local regional nodal metastases and possible peritoneal carcinomatosis. The thoracic CT scans showed extensive pneumomediastinum that tracked into the soft tissues of the neck, which given the history of vomiting also raised concern for esophageal perforation. There was still no evidence of mediastinal abscess or fat stranding. Additionally, a left subclavian vein port catheter, which terminates with tip at the cavoatrial junction of the superior vena cava can also be seen on the image. Discussion: Spontaneous Pneumomediastinum, also known as Hamman syndrome, is defined by the uncommon incidence of free air in the mediastinum due to the bursting of alveoli, as a result of extended spells of shouting, coughing, or vomiting.1,2 The condition is diagnosed when a clear cause (aerodigestive rupture, barotrauma, infection secondary to gas-forming organisms3 for pneumomediastinum cannot be clearly identified on diagnostic studies. Macklin and Macklin were the first to note the pathogenesis of the syndrome and explained that the common denominator to spontaneous pneumomediastinum was that increased alveolar pressure leads to alveolar rupture.3 Common clinical findings for spontaneous pneumomediastinum include: chest pain, dyspnea, cough, and emesis.4 The condition is not always readily recognized on initial presentation in part for its rare incidence, estimated to be approximately 1 in every 44,500 ED patients3and also because of the non-specific presenting symptoms. For this patient, there was no clear singular cause, and therefore she received care for spontaneous

  12. Anisotropic behaviour of transmission through thin superconducting NbN film in parallel magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Šindler, M., E-mail: sindler@fzu.cz [Institute of Physics ASCR, v. v. i., Cukrovarnická 10, CZ-162 53 Praha 6 (Czech Republic); Tesař, R. [Institute of Physics ASCR, v. v. i., Cukrovarnická 10, CZ-162 53 Praha 6 (Czech Republic); Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, CZ-121 16 Praha (Czech Republic); Koláček, J. [Institute of Physics ASCR, v. v. i., Cukrovarnická 10, CZ-162 53 Praha 6 (Czech Republic); Skrbek, L. [Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, CZ-121 16 Praha (Czech Republic)

    2017-02-15

    Highlights: • Transmission through thin NbN film in parallel magnetic field exhibits strong anisotropic behaviour in the terahertz range. • Response for a polarisation parallel with the applied field is given as weighted sum of superconducting and normal state contributions. • Effective medium approach fails to describe response for linear polarisation perpendicular to the applied magnetic field. - Abstract: Transmission of terahertz waves through a thin layer of the superconductor NbN deposited on an anisotropic R-cut sapphire substrate is studied as a function of temperature in a magnetic field oriented parallel with the sample. A significant difference is found between transmitted intensities of beams linearly polarised parallel with and perpendicular to the direction of applied magnetic field.

  13. Spontaneous lateral temporal encephalocele.

    Science.gov (United States)

    Tuncbilek, Gokhan; Calis, Mert; Akalan, Nejat

    2013-01-01

    A spontaneous encephalocele is one that develops either because of embryological maldevelopment or from a poorly understood postnatal process that permits brain herniation to occur. We here report a rare case of lateral temporal encephalocele extending to the infratemporal fossa under the zygomatic arch. At birth, the infant was noted to have a large cystic mass in the right side of the face. After being operated on initially in another center in the newborn period, the patient was referred to our clinic with a diagnosis of temporal encephalocele. He was 6 months old at the time of admission. Computerized tomography scan and magnetic resonance imaging studies revealed a 8 × 9 cm fluid-filled, multiloculated cystic mass at the right infratemporal fossa. No intracranial pathology or connection is seen. The patient was operated on to reduce the distortion effect of the growing mass. The histopathological examination of the sac revealed well-differentiated mature glial tissue stained with glial fibrillary acid protein. This rare clinical presentation of encephaloceles should be taken into consideration during the evaluation of the lateral facial masses in the infancy period, and possible intracranial connection should be ruled out before surgery to avoid complications.

  14. Spontaneous intracranial hypotension

    International Nuclear Information System (INIS)

    Haritanti, A.; Karacostas, D.; Drevelengas, A.; Kanellopoulos, V.; Paraskevopoulou, E.; Lefkopoulos, A.; Economou, I.; Dimitriadis, A.S.

    2009-01-01

    Spontaneous intracranial hypotension (SIH) is an uncommon but increasingly recognized syndrome. Orthostatic headache with typical findings on magnetic resonance imaging (MRI) are the key to diagnosis. Delayed diagnosis of this condition may subject patients to unnecessary procedures and prolong morbidity. We describe six patients with SIH and outline the important clinical and neuroimaging findings. They were all relatively young, 20-54 years old, with clearly orthostatic headache, minimal neurological signs (only abducent nerve paresis in two) and diffuse pachymeningeal gadolinium enhancement on brain MRI, while two of them presented subdural hygromas. Spinal MRI was helpful in detecting a cervical cerebrospinal fluid leak in three patients and dilatation of the vertebral venous plexus with extradural fluid collection in another. Conservative management resulted in rapid resolution of symptoms in five patients (10 days-3 weeks) and in one who developed cerebral venous sinus thrombosis, the condition resolved in 2 months. However, this rapid clinical improvement was not accompanied by an analogous regression of the brain MR findings that persisted on a longer follow-up. Along with recent literature data, our patients further point out that SIH, to be correctly diagnosed, necessitates increased alertness by the attending physician, in the evaluation of headaches

  15. Genetics Home Reference: primary spontaneous pneumothorax

    Science.gov (United States)

    ... Home Health Conditions Primary spontaneous pneumothorax Primary spontaneous pneumothorax Printable PDF Open All Close All Enable Javascript ... view the expand/collapse boxes. Description Primary spontaneous pneumothorax is an abnormal accumulation of air in the ...

  16. The inclusion of long-range polarisation functions in calculations of low-energy e+-H2 scattering using the Kohn method

    International Nuclear Information System (INIS)

    Armour, E.A.G.; Plummer, M.

    1989-01-01

    An explanation is given of why it is necessary to include long-range polarisation functions in the trial function when carrying out Kohn calculations of low-energy positron (and electron) scattering by atoms and simple molecules. The asymptotic form of these functions in low-energy e + -H 2 scattering is deduced. Appropriate functions with this asymptotic form are used to represent the closed-channel part of the wavefunction in a Kohn calculation of the lowest partial wave of Σ u + symmetry in e + -H 2 scattering at very low energies. For k≤0.03a 0 -1 , the results obtained are in good agreement with those obtained using the Born approximation and the asymptotic forms of the static and polarisation potentials. The relationship is pointed out between this method of taking into account long-range polarisation and the polarised pseudostate method used in R-matrix calculations. (author)

  17. Ziprasidone-induced spontaneous orgasm.

    Science.gov (United States)

    Boora, K; Chiappone, K; Dubovsky, S; Xu, J

    2010-06-01

    Neuroleptic treatment in schizophrenic patients has been associated with sexual dysfunction, including impotence and decreased libido. Spontaneous ejaculation without sexual arousal during typical antipsychotic treatment is a rare condition that has been described with zuclopentixol, trifluoperazine, and thiothixene. Here, we are reporting a case of spontaneous orgasm with ziprasidone in a bipolar patient. This patient began to repeatedly experience spontaneous sexual arousal and orgasm, which she had never experienced in the past. Ziprasidone might be causing an increase in sexual orgasm by 5-HT2 receptor antagonism, which preclinical evidence suggests that it facilitates dopamine release in the cortex.

  18. Horizontal cryostat for polarized proton targets; Cryostat horizontal pour cibles de protons polarises

    Energy Technology Data Exchange (ETDEWEB)

    Roubeau, P M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-11-15

    Continuously fed horizontal cryostat to be used for polarized proton targets; includes: 1 standard storage dewar commercially available; 2 shifting of dewar requiring 10 minutes, without any warming of the target; 3 no conventional nitrogen cooled shield but rather taking advantage of the cold helium vapours evaporated in the transfer line and/or the helium evaporated to cool the polarized crystal; 4 a heat exchanger which reduces by a factor of two the consumption of helium lowering in the same ratio the transfer line and/or the helium evaporated to cool the polarized crystal; 5 regulation of the temperature by means of a needle valve included in the superfluid helium line. This cryostat, used in conjunction with a 1000 l/s pump allows one to maintain at 1.06 deg. K a target, in which is dissipated 1 watt hyper frequency power, with an helium consumption of 40 litres/day (measured directly in the storage dewar). (author) [French] Description d'un cryostat horizontal, a alimentation continue, pour cible de protons polarises, presentant les caracteristiques suivantes: 1 utilisation de vases de stockage de modele commercial; 2 echange de vase en 10 minutes sans rechauffement; 3 absence d'azote liquide remplace par les vapeurs froides de l'helium evapore dans la canalisation de transfert et/ou les vapeurs de l'helium evapore pour refroidir le cristal polarise; 4 utilisation d'un echangeur qui aboutit a reduire de moitie la consommation d'helium, donc la pression d'evaporation, et qui permet, pour une pompe donnee, d'abaisser la temperature de fonctionnement de 0.1 degre environ; 5 reglage de la temperature au moyen d'une vanne a aiguille placee sur le circuit d'helium prerefroidi (superfluide). Ce cryostat, utilise avec une pompe de 1000 l/s permet de maintenir a une temperature de 1.06 deg. K une cible dans laquelle est dissipee une puissance d'hyperfrequence de 1 watt, moyennant une consommation d'helium de 40 litres/jour (mesuree dans le vase de stockage). (auteur)

  19. Hyperon polarisation in the reaction p-bar sup 1 sup 2 C -> LAMBDA-bar LAMBDA X

    CERN Document Server

    Pomp, S; Bröders, R; Bunker, B; Dennert, H; Eisenstein, R E; Eyrich, W; Fischer, H; Franklin, G; Franz, J; Geyer, R; Harris, P; Hauffe, J; Hertzog, D; Johansson, T; Jones, T; Kilian, K; Kraft, R A; Meyer, C; Oelert, W; Quinn, B; Röhrich, K; Rössle, E; Sachs, K; Schmitt, H; Schumacher, R; Sefzick, T; Stinzing, F; Tayloe, R; Todenhagen, R; Traneus, E; Wirth, S

    2000-01-01

    Data from the p-bar sup 1 sup 2 C -> LAMBDA-bar LAMBDA X reaction, collected by the PS185 experiment at antiproton momenta around 1.44 GeV/c, 1.66 GeV/c and 1.77 GeV/c, have been analyzed and the LAMBDA and LAMBDA-bar polarisations have been extracted. The events are classified as quasi-free or non-quasi-free and it is found that the polarisations for LAMBDA and LAMBDA-bar differ in the latter case. Such an effect comes from differences in the interaction of the outgoing LAMBDA and LAMBDA-bar with the residual nucleus and the measurement constitutes the first information on LAMBDA-bar interaction with nuclear matter.

  20. A Monte Carlo evaluation of analytical multiple scattering corrections for unpolarised neutron scattering and polarisation analysis data

    International Nuclear Information System (INIS)

    Mayers, J.; Cywinski, R.

    1985-03-01

    Some of the approximations commonly used for the analytical estimation of multiple scattering corrections to thermal neutron elastic scattering data from cylindrical and plane slab samples have been tested using a Monte Carlo program. It is shown that the approximations are accurate for a wide range of sample geometries and scattering cross-sections. Neutron polarisation analysis provides the most stringent test of multiple scattering calculations as multiply scattered neutrons may be redistributed not only geometrically but also between the spin flip and non spin flip scattering channels. A very simple analytical technique for correcting for multiple scattering in neutron polarisation analysis has been tested using the Monte Carlo program and has been shown to work remarkably well in most circumstances. (author)

  1. Measurement of charged current deep inelastic scattering cross sections with a longitudinally polarised electron beam at HERA

    International Nuclear Information System (INIS)

    Chekanov, S.; Derrick, M.; Magill, S.

    2008-12-01

    Measurements of the cross sections for charged current deep inelastic scattering in e - p collisions with longitudinally polarised electron beams are presented. The measurements are based on a data sample with an integrated luminosity of 175 pb -1 collected with the ZEUS detector at HERA at a centre-of-mass energy of 318 GeV. The total cross section is given for positively and negatively polarised electron beams. The differential cross-sections dσ/dQ 2 , dσ/dx and dσ/dy are presented for Q 2 >200 GeV 2 . The double-differential cross-section d 2 σ/dxdQ 2 is presented in the kinematic range 280 2 and 0.015< x<0.65. The measured cross sections are compared with the predictions of the Standard Model. (orig.)

  2. Spatial and spectral image distortions caused by diffraction of an ordinary polarised light beam by an ultrasonic wave

    Energy Technology Data Exchange (ETDEWEB)

    Machikhin, A S; Pozhar, V E [Scientific and Technological Centre of Unique Instrumentation, Russian Academy of Sciences, Moscow (Russian Federation)

    2015-02-28

    We consider the problem of determining the spatial and spectral image distortions arising from anisotropic diffraction by ultrasonic waves in crystals with ordinary polarised light (o → e). By neglecting the small-birefringence approximation, we obtain analytical solutions that describe the dependence of the diffraction angles and wave mismatch on the acousto-optic (AO) interaction geometry and crystal parameters. The formulas derived allow one to calculate and analyse the magnitude of diffraction-induced spatial and spectral image distortions and to identify the main types of distortions: chromatic compression and trapezoidal deformation. A comparison of the values of these distortions in the diffraction of ordinary and extraordinary polarised light shows that they are almost equal in magnitude and opposite in signs, so that consistent diffraction (o → e → o or e → o → e) in two identical AO cells rotated through 180° in the plane of diffraction can compensate for these distortions. (diffraction of radiation)

  3. Polarisation of valence and non-strange sea quarks in the nucleon from semi-inclusive spin asymmetries

    CERN Document Server

    AUTHOR|(CDS)2067425; Arvidson, A; Badelek, B; Ballintijn, M K; Bardin, G; Baum, G; Berglund, P; Betev, L; Bird, I G; Birsa, R; Björkholm, P; Bonner, B E; De Botton, N R; Bradamante, Franco; Bressan, A; Bültmann, S; Burtin, E; Cavata, C; Crabb, D; Cranshaw, J; Çuhadar-Dönszelmann, T; Dalla Torre, S; Van Dantzig, R; Deshpande, A A; Dhawan, S K; Dulya, C M; Dyring, A; Eichblatt, S; Faivre, Jean-Claude; Fasching, D; Feinstein, F; Fernández, C; Frois, Bernard; Garzón, J A; Gaussiran, T; Giorgi, M A; von Goeler, E; Gómez, A; Gracia, G; De Groot, N; Grosse-Perdekamp, M; Gülmez, E; Von Harrach, D; Hasegawa, T; Hautle, P; Hayashi, N; Heusch, C A; Horikawa, N; Hughes, V W; Igo, G; Ishimoto, S; Iwata, T; Kabuss, E M; Kageya, T; Karev, A G; Ketel, T; Kessler, H J; Kishi, A; Kiselev, Yu F; Klostermann, L; Krämer, Dietrich; Krivokhizhin, V G; Kröger, W; Kyynäräinen, J; Lamanna, M; Layda, T; Landgraf, U; Le Goff, J M; Lehár, F; de Lesquen, A; Lichtenstadt, J; Litmaath, M; López-Ponte, S; Loewe, M; Magnon, A; Mallot, G K; Marie, F; Martin, A; Martino, J; Matsuda, T; Mayes, B W; McCarthy, J S; Medved, K S; Van Middelkoop, G; Miller, D; Mori, K; Moromisato, J H; Nagaitsev, A P; Nassalski, J P; Naumann, Lutz; Niinikoski, T O; Oberski, J; Ogawa, A; Ozben, C; Penzo, Aldo L; Pérez, C; Perrot-Kunne, F; Peshekhonov, V D; Piegaia, R; Pinsky, L; Platchkov, S K; Pló, M; Pose, D; Postma, H; Pretz, J; Pussieux, T; Pyrlik, J; Reyhancan, I; Rijllart, A; Roberts, J B; Rock, S E; Rodríguez, M; Rondio, Ewa; Rosado, A; Dabo, I; Saborido, J; Sandacz, A; Savin, I A; Schiavon, R P; Schüler, K P; Segel, R E; Seitz, R; Semertzidis, Y K; Sergeev, S; Sever, F; Shanahan, P; Sichtermann, E P; Smirnov, G I; Staude, A; Steinmetz, A; Stiegler, U; Stuhrmann, H B; Szleper, M; Teichert, K M; Tessarotto, F; Velasco, M; Vogt, J; Voss, Rüdiger; Weinstein, R; Whitten, C; Windmolders, R; Willumeit, R; Wislicki, W; Witzmann, A; Zanetti, A M; Zhao, J; Torre, S Dalla

    1996-01-01

    We present a measurement of semi-inclusive spin asymmetries for positively and negatively charged hadrons from deep inelastic scattering of polarised muons on polarised protons and deuterons in the range 0.003

  4. Polarisation-preserving photon frequency conversion from a trapped-ion-compatible wavelength to the telecom C-band

    Science.gov (United States)

    Krutyanskiy, V.; Meraner, M.; Schupp, J.; Lanyon, B. P.

    2017-09-01

    We demonstrate polarisation-preserving frequency conversion of single-photon-level light at 854 nm, resonant with a trapped-ion transition and qubit, to the 1550-nm telecom C band. A total photon in / fiber-coupled photon out efficiency of ˜30% is achieved, for a free-running photon noise rate of ˜60 Hz. This performance would enable telecom conversion of 854 nm polarisation qubits, produced in existing trapped-ion systems, with a signal-to-noise ratio greater than 1. In combination with near-future trapped-ion systems, our converter would enable the observation of entanglement between an ion and a photon that has travelled more than 100 km in optical fiber: three orders of magnitude further than the state-of-the-art.

  5. Contribution to the experimental study of the polarized liquid helium-3; Contributions a l'etude experimentale de l'helium-3 liquide polarise

    Energy Technology Data Exchange (ETDEWEB)

    Villard, B

    1999-07-15

    Spin-polarized liquid helium-3 is prepared by laser optical pumping in low magnetic field and at room temperature, prior to fast liquefaction of the polarized sample. The use of a new helium-3 cryostat enabled us to obtain liquid helium-3 with polarization rates up to 25 % at well-stabilized temperatures (around 0.5 K). We could thereby study the effect of nuclear polarization on liquid-vapour equilibrium, and particularly on the saturated vapour pressure. Very sensitive capacitive gauges were developed. We estimated (to first order in M{sup 2}) the expected effects when the polarization M is suddenly destroyed. These effects were experimentally observed in helium-3/helium-4 mixtures, in pure helium-3, only a transient increase in pressure has been recorded. We then describe in a third part a preliminary experiment which aimed at determining the longitudinal relaxation time T1 in mixtures. Relaxation on the walls is efficiently reduced by a cesium coating and T1s of order 20 minutes were observed. A careful determination of the helium-3 concentration in the liquid phase was made. Finally we studied the effects of dipolar field on transverse polarisation decay in our strongly polarized samples. We observed the free precession of polarization after a NMR pulse, and analysed in detail its decay time constant as a function of different parameters. This time constant drastically varied with the tipping angle, an effect which could be linked to NMR dynamical instabilities. (author)

  6. fields

    Directory of Open Access Journals (Sweden)

    Brad J. Arnold

    2014-07-01

    Full Text Available Surface irrigation, such as flood or furrow, is the predominant form of irrigation in California for agronomic crops. Compared to other irrigation methods, however, it is inefficient in terms of water use; large quantities of water, instead of being used for crop production, are lost to excess deep percolation and tail runoff. In surface-irrigated fields, irrigators commonly cut off the inflow of water when the water advance reaches a familiar or convenient location downfield, but this experience-based strategy has not been very successful in reducing the tail runoff water. Our study compared conventional cutoff practices to a retroactively applied model-based cutoff method in four commercially producing alfalfa fields in Northern California, and evaluated the model using a simple sensor system for practical application in typical alfalfa fields. These field tests illustrated that the model can be used to reduce tail runoff in typical surface-irrigated fields, and using it with a wireless sensor system saves time and labor as well as water.

  7. Quark potential of spontaneous strings

    International Nuclear Information System (INIS)

    German, G.; Kleinert, H.

    1989-01-01

    The authors present some recent developments in string models with an extrinsic curvature term in action. Particular emphasis is placed upon the static quark potential and on the thermal deconfinement properties of spontaneous strings

  8. Hematome Extra - Dural Rachidien Spontane

    Directory of Open Access Journals (Sweden)

    Cl. Gros

    1967-01-01

    Full Text Available Four personal cases of Spontaneous Spinal Epidurdl Hemerrhage are Reported. And 29 additional cases have been analysed by reviewing the literature. The clinical radiologcal and surgical aspects were discussed.

  9. Spontaneous intraorbital hematoma: case report

    Directory of Open Access Journals (Sweden)

    Vinodan Paramanathan

    2010-12-01

    Full Text Available Vinodan Paramanathan, Ardalan ZolnourianQueen's Hospital NHS Foundation Trust, Burton on Trent, Staffordshire DE13 0RB, UKAbstract: Spontaneous intraorbital hematoma is an uncommon clinical entity seen in ophthalmology practice. It is poorly represented in the literature. Current evidence attributes it to orbital trauma, neoplasm, vascular malformations, acute sinusitis, and systemic abnormalities. A 65-year-old female presented with spontaneous intraorbital hematoma manifesting as severe ocular pains, eyelid edema, proptosis, and diplopia, without a history of trauma. Computer tomography demonstrated a fairly well defined extraconal lesion with opacification of the paranasal sinuses. The principal differential based on all findings was that of a spreading sinus infection and an extraconal tumor. An unprecedented finding of a spontaneous orbital hematoma was discovered when the patient was taken to theater. We discuss the rarity of this condition and its management.Keywords: hemorrhage, ophthalmology, spontaneous, intra-orbital, hematoma

  10. LHCb: Photon polarisation B in $b \\rightarrow s\\gamma$ using B $\\rightarrow$ K$^*$e$^+$e$^-$ at LHCb

    CERN Multimedia

    Nicol, Michelle

    2011-01-01

    Although the branching ratio of $b \\rightarrow s\\gamma$ has been measured to be consistent with that predicted by the Standard Model, new physics could still be present and detectable through analysing details of the decay process. In particular, the photon from the b is predominantly left handed in the SM, whereas additional right handed currents can arise in certain classes of new physics models. Access to the polarisation information is available via an angular analysis of $B \\rightarrow K^*e^+e^-$. Hadronic form factors render theoretical predictions over the whole $q^2$ (the dilepton invariant mass squared) range difficult . However, it has been shown that at low $q^2$, certain asymmetries providing information on the photon polarisation can be formed, where these uncertainties are controllable. This poster will present an overview of the method to measure the photon polarisation at the LHCb experiment at CERN by performing an angular analysis of $B \\rightarrow K^*e^+e^-$ at low $q^2$.

  11. Polarisation-based coincidence event discrimination: an in silico study towards a feasible scheme for Compton-PET

    Science.gov (United States)

    Toghyani, M.; Gillam, J. E.; McNamara, A. L.; Kuncic, Z.

    2016-08-01

    Current positron emission tomography (PET) systems use temporally localised coincidence events discriminated by energy and time-of-flight information. The two annihilation photons are in an entangled polarisation state and, in principle, additional information from the polarisation correlation of photon pairs could be used to improve the accuracy of coincidence classification. In a previous study, we demonstrated that in principle, the polarisation correlation information could be transferred to an angular correlation in the distribution of scattered photon pairs in a planar Compton camera system. In the present study, we model a source-phantom-detector system using Geant4 and we develop a coincidence classification scheme that exploits the angular correlation of scattered annihilation quanta to improve the accuracy of coincidence detection. We find a 22% image quality improvement in terms of the peak signal-to-noise ratio when scattered coincidence events are discriminated solely by their angular correlation, thus demonstrating the feasibility of this novel classification scheme. By integrating scatter events (both single-single and single-only) with unscattered coincidence events discriminated using conventional methods, our results suggest that Compton-PET may be a promising candidate for optimal emission tomographic imaging.

  12. Spontaneity and international marketing performance

    OpenAIRE

    Souchon, Anne L.; Hughes, Paul; Farrell, Andrew M.; Nemkova, Ekaterina; Oliveira, Joao S.

    2016-01-01

    The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. Purpose – The purpose of this paper is to ascertain how today’s international marketers can perform better on the global scene by harnessing spontaneity. Design/methodology/approach – The authors draw on contingency theory to develop a model of the spontaneity – international marketing performance relationship, and identify three potential m...

  13. Spontaneous ischaemic stroke in dogs

    DEFF Research Database (Denmark)

    Gredal, Hanne Birgit; Skerritt, G. C.; Gideon, P.

    2013-01-01

    Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms.......Translation of experimental stroke research into the clinical setting is often unsuccessful. Novel approaches are therefore desirable. As humans, pet dogs suffer from spontaneous ischaemic stroke and may hence offer new ways of studying genuine stroke injury mechanisms....

  14. Spontaneous calf haematoma: case report.

    Science.gov (United States)

    Zubaidah, N H; Liew, N C

    2014-02-01

    Spontaneous calf haematoma is a rare condition and few case reports have been published in the English literature. Common conditions like deep vein thrombosis and traumatic gastrocnemius muscle tear need to be considered when a patient presents with unilateral calf swelling and tenderness. Ultrasound and Magnetic Resonance Imaging are essential for confirmation of diagnosis. The purpose of this paper is to report on a rare case of spontaneous calf hematoma and its diagnosis and management.

  15. Quantifying emissions from spontaneous combustion

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-09-01

    Spontaneous combustion can be a significant problem in the coal industry, not only due to the obvious safety hazard and the potential loss of valuable assets, but also with respect to the release of gaseous pollutants, especially CO2, from uncontrolled coal fires. This report reviews methodologies for measuring emissions from spontaneous combustion and discusses methods for quantifying, estimating and accounting for the purpose of preparing emission inventories.

  16. Triggering and W-Polarisation Studies with CMS at the LHC

    CERN Document Server

    Marrouche, Jad

    2010-01-01

    Results from studies on the commissioning of the Global Calorimeter Trigger (GCT) of the CMS experiment are presented. Event-by-event comparisons of the hardware with a bit-level software emulation are used to achieve 100% agreement for all trigger quantities. In addition, a missing energy trigger based on jets is motivated using a simulation study, and consequently implemented and commissioned in the GCT. Furthermore, a templated-fit method for measuring the polarisation of W bosons at the LHC in the Helicity Frame is developed, and validated in simulation. An analysis of the first 3.2/pb of sqrt(s) = 7 TeV LHC data in the muon channel yields values of (fL − fR)+ = 0.347 ± 0.070, f0+ = 0.240 ± 0.176, and (fL − fR)− = 0.097 ± 0.088, f0− = 0.262 ± 0.196 for positive and negative charges respectively. The errors quoted are statistical. A preliminary systematic study is also presented.

  17. Evolution of oxygen reduction current and biofilm on stainless steels cathodically polarised in natural aerated seawater

    Energy Technology Data Exchange (ETDEWEB)

    Faimali, Marco [ISMAR-CNR, Via De Marini 6, 16149 Genoa (Italy)], E-mail: marco.faimali@ismar.cnr.it; Chelossi, Elisabetta; Garaventa, Francesca; Corra, Christian; Greco, Giuliano; Mollica, Alfonso [ISMAR-CNR, Via De Marini 6, 16149 Genoa (Italy)

    2008-12-01

    The aim of a series of works recently performed at ISMAR was to provide new useful information for a better understanding of the mechanisms by which bacteria settlement causes corrosion on Stainless Steels (SS) and similar active-passive alloys exposed to seawater. In this work, the evolutions of cathodic current, bacteria population, and electronic structure of the passive layer were investigated on SS samples polarised at fixed potentials during their exposure to natural seawater. It was found that, during the first phase of biofilm growth, cathodic current increase is proportional to the number of settled bacteria at each fixed potential. However, the proportionality factor between settled bacteria and cathodic current depends on imposed potential. In particular, the proportionality factor strongly decreases when the potential is increased above a critical value close to -150 mV Ag/AgCl. This effect seems to be correlated with the electronic structure of the passive layer. Indeed, the outer part of the passive layer on tested SS was found to behave like a conductor at potentials more active than -150 mV Ag/AgCl, and like an n-type semiconductor at more noble potentials.

  18. Evolution of oxygen reduction current and biofilm on stainless steels cathodically polarised in natural aerated seawater

    International Nuclear Information System (INIS)

    Faimali, Marco; Chelossi, Elisabetta; Garaventa, Francesca; Corra, Christian; Greco, Giuliano; Mollica, Alfonso

    2008-01-01

    The aim of a series of works recently performed at ISMAR was to provide new useful information for a better understanding of the mechanisms by which bacteria settlement causes corrosion on Stainless Steels (SS) and similar active-passive alloys exposed to seawater. In this work, the evolutions of cathodic current, bacteria population, and electronic structure of the passive layer were investigated on SS samples polarised at fixed potentials during their exposure to natural seawater. It was found that, during the first phase of biofilm growth, cathodic current increase is proportional to the number of settled bacteria at each fixed potential. However, the proportionality factor between settled bacteria and cathodic current depends on imposed potential. In particular, the proportionality factor strongly decreases when the potential is increased above a critical value close to -150 mV Ag/AgCl. This effect seems to be correlated with the electronic structure of the passive layer. Indeed, the outer part of the passive layer on tested SS was found to behave like a conductor at potentials more active than -150 mV Ag/AgCl, and like an n-type semiconductor at more noble potentials

  19. Azimuthal asymmetries of charged hadrons produced by high-energy muons scattered off longitudinally polarised deuterons

    International Nuclear Information System (INIS)

    Alekseev, M.G.; Colantoni, M.; Maggiora, A.; Alexakhin, V.Yu.; Alexeev, G.D.; Efremov, A.; Finger, M.; Gavrichtchouk, O.P.; Gushterski, R.; Guskov, A.; Ivanov, O.; Ivanshin, Yu.; Kroumchtein, Z.V.; Nagaytsev, A.; Olshevsky, A.G.; Perevalova, E.; Peshekhonov, D.V.; Pontecorvo, G.; Rapatsky, V.; Sapozhnikov, M.G.; Savin, I.A.; Shevchenko, O.Yu.; Sissakian, A.N.; Slunecka, M.; Smirnov, G.I.; Tkatchev, L.G.; Vlassov, N.V.; Zemlyanichkina, E.; Zhuravlev, N.; Alexandrov, Yu.; Zavertyaev, M.; Amoroso, A.; Balestra, F.; Bertini, R.; Bussa, M.P.; Chiosso, M.; Garfagnini, R.; Gnesi, I.; Grasso, A.; Kotzinian, A.M.; Maggiora, M.; Parsamyan, B.; Piragino, G.; Rocco, E.; Sosio, S.; Austregesilo, A.; Badelek, B.; Gazda, R.; Klimaszewski, K.; Kurek, K.; Nassalski, J.; Pawlukiewicz-Kaminska, B.; Rondio, E.; Sandacz, A.; Wislicki, W.; Barth, J.; Klein, F.; Panknin, R.; Pretz, J.; Windmolders, R.; Baum, G.; Bedfer, Y.; Burtin, E.; El Alaoui, A.; Ferrero, A.; Hose, N. d'; Jegou, G.; Kunne, F.; Le Goff, J.M.; Magnon, A.; Marchand, C.; Neyret, D.; Platchkov, S.; Robinet, F.; Bernhard, J.; Chaberny, D.; Harrach, D. von; Jasinski, P.; Kabuss, E.; Koblitz, S.; Korzenev, A.; Ostrick, M.; Pochodzalla, J.; Siebert, H.W.; Bettinelli, M.; Duennweber, W.; Faessler, M.; Geyer, R.; Rajotte, J.F.; Schlueter, T.; Uman, I.; Zvyagin, A.; Birsa, R.; Bravar, A.; Dalla Torre, S.; Gobbo, B.; Tessaro, S.; Tessarotto, F.; Bisplinghoff, J.; Eversheim, P.D.; Hinterberger, F.; Jahn, R.; Joosten, R.; Massmann, F.; Negrini, T.; Bordalo, P.; Franco, C.; Nunes, A.S.; Quintans, C.; Ramos, S.; Santos, H.; Silva, L.; Bradamante, F.; Bressan, A.; Duic, V.; Giorgi, M.; Levorato, S.; Martin, A.; Pesaro, G.; Sbrizzai, G.; Schiavon, P.; Sozzi, F.; Takekawa, S.; Brona, G.; Chung, S.U.; Friedrich, J.M.; Grabmueller, S.; Grube, B.; Haas, F.; Hoeppner, C.; Ketzer, B.; Konopka, R.; Kraemer, M.; Kuhn, R.; Mann, A.; Nagel, T.; Neubert, S.; Paul, S.; Schmitt, L.; Uhl, S.; Weitzel, Q.; Cicuttin, A.; Crespo, M.L.; Diaz, V.; Das, S.; Dasgupta, S.S.; Dhara, L.; Sarkar, S.; Sinha, L.; Denisov, O.Yu.; Donskov, S.V.; Filin, A.; Khaustov, G.V.; Khokhlov, Yu.A.; Kolosov, V.N.; Konstantinov, V.F.; Lednev, A.A.; Mikhailov, Yu.V.; Nikolaenko, V.I.; Polyakov, V.A.; Ryabchikov, D.I.; Samoylenko, V.D.; Doshita, N.; Kondo, K.; Eyrich, W.; Lehmann, A.; Richter, A.; Schroeder, W.; Teufel, A.; Finger, M.; Fischer, H.; Heinsius, F.H.; Herrmann, F.; Kang, D.; Koenigsmann, K.; Lauser, L.; Nerling, F.; Schill, C.; Schopferer, S.; Vossen, A.; Wollny, H.; Gautheron, F.; Hess, C.; Kisselev, Yu.; Koivuniemi, J.H.; Meyer, W.; Reicherz, G.; Gerassimov, S.; Konorov, I.; Goertz, S.; Hasegawa, T.; Matsuda, T.; Horikawa, N.; Ishimoto, S.; Ilgner, C.; Iwata, T.; Michigami, T.; Kouznetsov, O.; CEA IRFU/SPhN Saclay, Gif-sur-Yvette; Soltan Institute for Nuclear Studies and University of Warsaw, Warsaw; Lichtenstadt, J.; Moinester, M.A.; Mallot, G.K.; Stolarski, M.; Marzec, J.; Padee, A.; Sulej, R.; Zaremba, K.; Ziembicki, M.; Mutter, A.; Panzieri, D.; Polak, J.; Srnka, A.; Sulc, M.; Zhao, J.

    2010-01-01

    Azimuthal asymmetries in semi-inclusive production of positive (h + ) and negative hadrons (h - ) have been measured by scattering 160 GeV muons off longitudinally polarised deuterons at CERN. The asymmetries were decomposed in several terms according to their expected modulation in the azimuthal angle φ of the outgoing hadron. Each term receives contributions from one or several spin and transverse-momentum-dependent parton distribution and fragmentation functions. The amplitudes of all φ-modulation terms of the hadron asymmetries integrated over the kinematic variables are found to be consistent with zero within statistical errors, while the constant terms are nonzero and equal for h + and h - within the statistical errors. The dependencies of the φ-modulated terms versus the Bjorken momentum fraction x, the hadron fractional momentum z, and the hadron transverse momentum p h T were studied. The x dependence of the constant terms for both positive and negative hadrons is in agreement with the longitudinal double-spin hadron asymmetries, measured in semi-inclusive deep-inelastic scattering. The x dependence of the sin φ-modulation term is less pronounced than that in the corresponding HERMES data. All other dependencies of the φ-modulation amplitudes are consistent with zero within the statistical errors. (orig.)

  20. SAR target recognition using behaviour library of different shapes in different incidence angles and polarisations

    Science.gov (United States)

    Fallahpour, Mojtaba Behzad; Dehghani, Hamid; Jabbar Rashidi, Ali; Sheikhi, Abbas

    2018-05-01

    Target recognition is one of the most important issues in the interpretation of the synthetic aperture radar (SAR) images. Modelling, analysis, and recognition of the effects of influential parameters in the SAR can provide a better understanding of the SAR imaging systems, and therefore facilitates the interpretation of the produced images. Influential parameters in SAR images can be divided into five general categories of radar, radar platform, channel, imaging region, and processing section, each of which has different physical, structural, hardware, and software sub-parameters with clear roles in the finally formed images. In this paper, for the first time, a behaviour library that includes the effects of polarisation, incidence angle, and shape of targets, as radar and imaging region sub-parameters, in the SAR images are extracted. This library shows that the created pattern for each of cylindrical, conical, and cubic shapes is unique, and due to their unique properties these types of shapes can be recognised in the SAR images. This capability is applied to data acquired with the Canadian RADARSAT1 satellite.

  1. Towards the measurement of photon polarisation in the decay $B^+ \\to K^+ π^- π^+ \\gamma$

    CERN Document Server

    AUTHOR|(CDS)2083955; Blanc, Frederic

    This thesis presents a study of the flavour-changing neutral-current radiative $B^+ \\rightarrow K^+ \\pi^- \\pi^+ \\gamma$ decay performed using $3\\, \\rm{fb}^{-1}$ of data collected with the LHCb detector in proton-proton collisions at $7$ and $8\\,$TeV centre-of-mass energies. The study of radiative decays with three scalar hadrons in the final state gives access to the polarisation of the photon, one of the very few predictions of the Standard Model of particle physics that has not been precisely tested experimentally and that is sensitive to new physics effects in the $b \\rightarrow s \\gamma$ penguin loop. Nearly $14\\,000$ signal events, containing all possible intermediate resonances with a $K^+ \\pi^- \\pi^+$ final state in the $[1,2]\\, \\rm{GeV}/\\it{c}^2$ mass interval, are reconstructed and selected in the data sample. The distribution of the angle of the photon direction with respect to the plane defined by the final-state hadrons in their rest frame is studied in intervals of $K^+ \\pi^- \\pi^+$ mass and the...

  2. Azimuthal asymmetries of charged hadrons produced in high-energy muon scattering off longitudinally polarised deuterons

    CERN Document Server

    Adolph, C; Akhunzyanov, R; Alexeev, M G; Alexeev, G D; Amoroso, A; Andrieux, V; Anfimov, N V; Anosov, V; Augsten, K; Augustyniak, W; Austregesilo, A; Azevedo, C D R; Badełek, B; Balestra, F; Ball, M; Barth, J; Beck, R; Bedfer, Y; Bernhard, J; Bicker, K; Bielert, E R; Birsa, R; Bodlak, M; Bordalo, P; Bradamante, F; Braun, C; Bressan, A; Buchele, M; Chang, W-C; Chatterjee, C; Chiosso, M; Choi, I; Chung, S-U; Cicuttin, A; Crespo, M L; Curiel, Q; Dalla Torre, S; Dasgupta, S S; Dasgupta, S; Denisov, O Yu; Dhara, L; Donskov, S V; Doshita, N; Dreisbach, Ch; Duic, V; Dunnweber, W; Dziewiecki, M; Efremov, A; Eversheim, P D; Eyrich, W; Faessler, M; Ferrero, A; Finger, M; Finger jr, M; Fischer, H; Franco, C; du Fresne von Hohenesche, N; Friedrich, J M; Frolov, V; Fuchey, E; Gautheron, F; Gavrichtchouk, O P; Gerassimov, S; Giarra, J; Giordano, F; Gnesi, I; Gorzellik, M; Grabmuller, S; Grasso, A; Grosse Perdekamp, M; Grube, B; Grussenmeyer, T; Guskov, A; Haas, F; Hahne, D; Hamar, G; von Harrach, D; Heinsius, F H; Heitz, R; Herrmann, F; Horikawa, N; d’Hose, N; Hsieh, C-Y; Huber, S; Ishimoto, S; Ivanov, A; Ivanshin, Yu; Iwata, T; Jary, V; Joosten, R; Jorg, P; Kabuß, E; Ketzer, B; Khaustov, G V; Khokhlov, Yu A; Kisselev, Yu; Klein, F; Klimaszewski, K; Koivuniemi, J H; Kolosov, V N; Kondo, K; Konigsmann, K; Konorov, I; Konstantinov, V F; Kotzinian, A M; Kouznetsov, O M; Kramer, M; Kremser, P; Krinner, F; Kroumchtein, Z V; Kulinich, Y; Kunne, F; Kurek, K; Kurjata, R P; Lednev, A A; Lehmann, A; Levillain, M; Levorato, S; Lian, Y-S; Lichtenstadt, J; Longo, R; Maggiora, A; Magnon, A; Makins, N; Makke, N; Mallot, G K; Marianski, B; Martin, A; Marzec, J; Matousek, J; Matsuda, H; Matsuda, T; Meshcheryakov, G V; Meyer, M; Meyer, W; Mikhailov, Yu V; Mikhasenko, M; Mitrofanov, E; Mitrofanov, N; Miyachi, Y; Nagaytsev, A; Nerling, F; Neyret, D; Novy, J; Nowak, W-D; Nukazuka, G; Nunes, A S; Olshevsky, A G; Orlov, I; Ostrick, M; Panzieri, D; Parsamyan, B; Paul, S; Peng, J-C; Pereira, F; Pesek, M; Peshekhonov, D V; Pierre, N; Platchkov, S; Pochodzalla, J; Polyakov, V A; Pretz, J; Quaresma, M; Quintans, C; Ramos, S; Regali, C; Reicherz, G; Riedl, C; Roskot, M; Rossiyskaya, N S; Ryabchikov, D I; Rybnikov, A; Rychter, A; Salac, R; Samoylenko, V D; Sandacz, A; Santos, C; Sarkar, S; Savin, I A; Sawada, T; Sbrizzai, G; Schiavon, P; Schmidt, K; Schmieden, H; Schonning, K; Seder, E; Selyunin, A; Silva, L; Sinha, L; Sirtl, S; Slunecka, M; Smolik, J; Srnka, A; Steffen, D; Stolarski, M; Subrt, O; Sulc, M; Suzuki, H; Szabelski, A; Szameitat, T; Sznajder, P; Takekawa, S; Tasevsky, M; Tessaro, S; Tessarotto, F; Thibaud, F; Thiel, A; Tosello, F; Tskhay, V; Uhl, S; Veloso, J; Virius, M; Vondra, J; Wallner, S; Weisrock, T; Wilfert, M; ter Wolbeek, J; Zaremba, K; Zavada, P; Zavertyaev, M; Zemlyanichkina, E; Zhuravlev, N; Ziembicki, M; Zink, A

    2016-01-01

    Single hadron azimuthal asymmetries in the cross sections of positive and negative hadron production in muon semi-inclusive deep inelastic scattering off longitudinally polarised deuterons are determined using the 2006 COMPASS data and also all deuteron COMPASS data. For each hadron charge, the dependence of the azimuthal asymmetry on the hadron azimuthal angle $\\phi$ is obtained by means of a five-parameter fitting function that besides a $\\phi$-independent term includes four modulations predicted by theory: $\\sin\\phi$, $\\sin 2 \\phi$, $\\sin 3\\phi$ and $\\cos\\phi$. The amplitudes of the five terms have been first extracted for the data integrated over all kinematic variables. In further fits, the $\\phi$-dependence is determined as a function of one of three kinematic variables (Bjorken-$x$, fractional energy of virtual photon taken by the outgoing hadron and hadron transverse momentum), while disregarding the other two. Except the $\\phi$-independent term, all the modulation amplitudes are very small, and no cl...

  3. Spontaneous emission spectra and simulating multiple spontaneous generation coherence in a five-level atomic medium

    International Nuclear Information System (INIS)

    Li Jiahua; Liu Jibing; Qi Chunchao; Chen Aixi

    2006-01-01

    We investigate the features of the spontaneous emission spectra in a coherently driven cold five-level atomic system by means of a radio frequency (rf) or microwave field driving a hyperfine transition within the ground state. It is shown that a few interesting phenomena such as spectral-line narrowing, spectral-line enhancement, spectral-line suppression, and spontaneous emission quenching can be realized by modulating the frequency and intensity of the rf-driving field in our system. In the dressed-state picture of the coupling and rf-driving fields, we find that this coherently driven atomic system has three close-lying levels so that multiple spontaneously generated coherence (SGC) arises. Our considered atomic model can be found in real atoms, such as rubidium or sodium, so a corresponding experiment can be done to observe the expected phenomena related to SGC reported by Fountoulakis et al. [Phys. Rev. A 73, 033811 (2006)], since no rigorous conditions are required

  4. Spontaneous symmetry breaking in 4-dimensional heterotic string

    International Nuclear Information System (INIS)

    Maharana, J.

    1989-07-01

    The evolution of a 4-dimensional heterotic string is considered in the background of its massless excitations such as graviton, antisymmetric tensor, gauge fields and scalar bosons. The compactified bosonic coordinates are fermionized. The world-sheet supersymmetry requirement enforces Thirring-like four fermion coupling to the background scalar fields. The non-abelian gauge symmetry is exhibited through the Ward identities of the S-matrix elements. The spontaneous symmetry breaking mechanism is exhibited through the broken Ward identities. An effective 4-dimensional action is constructed and the consequence of spontaneous symmetry breaking is envisaged for the effective action. 19 refs

  5. Spontaneously broken supersymmetry and Poincare invariance

    International Nuclear Information System (INIS)

    Tata, X.R.; Sudarshan, E.C.G.; Schechter, J.M.

    1982-12-01

    It is argued that the spontaneous breakdown of global supersymmetry is consistent with unbroken Poincare invariance if and only if the supersymmetry algebra A = 0 is understood to mean the invariance of the dynamical variables phi under the transformations generated by the algebra, i.e. [A, phi] = 0 rather than as an operator equation. It is further argued that this weakening of the algebra does not alter any of the conclusions about supersymmetric quantum field theories that have been obtained using the original (stronger) form of the algebra

  6. Spontaneously broken supersymmetry and Poincare invariance

    International Nuclear Information System (INIS)

    Tata, X.R.; Sudarshan, E.C.G.; Schechter, J.M.

    1983-01-01

    It is argued that the spontaneous breakdown of global supersymmetry is consistent with unbroken Poincare invariance if and only if the supersymmetry algebra 'A=0' is understood to mean the invariance of the dynamical variables phi under the transformations generated by the algebra, i.e. [A, phi]=0 rather than as an operator equation. It is further argued that this 'weakening' of the algrebra does not alter any of the conclusions about supersymmetry quantum field theories that have been obtained using the original (stronger) form of the algebra. (orig.)

  7. Neutrino masses and spontaneously broken flavor symmetries

    International Nuclear Information System (INIS)

    Staudt, Christian

    2014-01-01

    We study the phenomenology of supersymmetric flavor models. We show how the predictions of models based on spontaneously broken non-Abelian discrete flavor symmetries are altered when we include so-called Kaehler corrections. Furthermore, we discuss anomaly-free discrete R symmetries which are compatible with SU(5) unification. We find a set of symmetries compatible with suppressed Dirac neutrino masses and a unique symmetry consistent with the Weinberg operator. We also study a pseudo-anomalous U(1) R symmetry which explains the fermion mass hierarchies and, when amended with additional singlet fields, ameliorates the fine-tuning problem.

  8. Centriole polarisation to the immunological synapse directs secretion from cytolytic cells of both the innate and adaptive immune systems

    Directory of Open Access Journals (Sweden)

    Arico Maurizo

    2011-06-01

    Full Text Available Abstract Background Cytolytic cells of the immune system destroy pathogen-infected cells by polarised exocytosis of secretory lysosomes containing the pore-forming protein perforin. Precise delivery of this lethal hit is essential to ensuring that only the target cell is destroyed. In cytotoxic T lymphocytes (CTLs, this is accomplished by an unusual movement of the centrosome to contact the plasma membrane at the centre of the immunological synapse formed between killer and target cells. Secretory lysosomes are directed towards the centrosome along microtubules and delivered precisely to the point of target cell recognition within the immunological synapse, identified by the centrosome. We asked whether this mechanism of directing secretory lysosome release is unique to CTL or whether natural killer (NK and invariant NKT (iNKT cytolytic cells of the innate immune system use a similar mechanism to focus perforin-bearing lysosome release. Results NK cells were conjugated with B-cell targets lacking major histocompatibility complex class I 721.221 cells, and iNKT cells were conjugated with glycolipid-pulsed CD1-bearing targets, then prepared for thin-section electron microscopy. High-resolution electron micrographs of the immunological synapse formed between NK and iNKT cytolytic cells with their targets revealed that in both NK and iNKT cells, the centrioles could be found associated (or 'docked' with the plasma membrane within the immunological synapse. Secretory clefts were visible within the synapses formed by both NK and iNKT cells, and secretory lysosomes were polarised along microtubules leading towards the docked centrosome. The Golgi apparatus and recycling endosomes were also polarised towards the centrosome at the plasma membrane within the synapse. Conclusions These results reveal that, like CTLs of the adaptive immune system, the centrosomes of NK and iNKT cells (cytolytic cells of the innate immune system direct secretory lysosomes to

  9. Polarisation observations of VY Canis Majoris H2O 532-441 620.701 GHz maser emission with HIFI

    Science.gov (United States)

    Harwit, M.; Houde, M.; Sonnentrucker, P.; Boogert, A. C. A.; Cernicharo, J.; De Beck, E.; Decin, L.; Henkel, C.; Higgins, R. D.; Jellema, W.; Kraus, A.; McCoey, C.; Melnick, G. J.; Menten, K. M.; Risacher, C.; Teyssier, D.; Vaillancourt, J. E.; Alcolea, J.; Bujarrabal, V.; Dominik, C.; Justtanont, K.; de Koter, A.; Marston, A. P.; Olofsson, H.; Planesas, P.; Schmidt, M.; Schöier, F. L.; Szczerba, R.; Waters, L. B. F. M.

    2010-10-01

    Context. Water vapour maser emission from evolved oxygen-rich stars remains poorly understood. Additional observations, including polarisation studies and simultaneous observation of different maser transitions may ultimately lead to greater insight. Aims: We have aimed to elucidate the nature and structure of the VY CMa water vapour masers in part by observationally testing a theoretical prediction of the relative strengths of the 620.701 GHz and the 22.235 GHz maser components of ortho H2O. Methods: In its high-resolution mode (HRS) the Herschel Heterodyne Instrument for the Far Infrared (HIFI) offers a frequency resolution of 0.125 MHz, corresponding to a line-of-sight velocity of 0.06 km s-1, which we employed to obtain the strength and linear polarisation of maser spikes in the spectrum of VY CMa at 620.701 GHz. Simultaneous ground based observations of the 22.235 GHz maser with the Max-Planck-Institut für Radioastronomie 100-m telescope at Effelsberg, provided a ratio of 620.701 GHz to 22.235 GHz emission. Results: We report the first astronomical detection to date of H2O maser emission at 620.701 GHz. In VY CMa both the 620.701 and the 22.235 GHz polarisation are weak. At 620.701 GHz the maser peaks are superposed on what appears to be a broad emission component, jointly ejected from the star. We observed the 620.701 GHz emission at two epochs 21 days apart, both to measure the potential direction of linearly polarised maser components and to obtain a measure of the longevity of these components. Although we do not detect significant polarisation levels in the core of the line, they rise up to approximately 6% in its wings. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Appendix (page 5) is only available in electronic form at http://www.aanda.org

  10. Centriole polarisation to the immunological synapse directs secretion from cytolytic cells of both the innate and adaptive immune systems.

    Science.gov (United States)

    Stinchcombe, Jane C; Salio, Mariolina; Cerundolo, Vincenzo; Pende, Daniela; Arico, Maurizo; Griffiths, Gillian M

    2011-06-28

    Cytolytic cells of the immune system destroy pathogen-infected cells by polarised exocytosis of secretory lysosomes containing the pore-forming protein perforin. Precise delivery of this lethal hit is essential to ensuring that only the target cell is destroyed. In cytotoxic T lymphocytes (CTLs), this is accomplished by an unusual movement of the centrosome to contact the plasma membrane at the centre of the immunological synapse formed between killer and target cells. Secretory lysosomes are directed towards the centrosome along microtubules and delivered precisely to the point of target cell recognition within the immunological synapse, identified by the centrosome. We asked whether this mechanism of directing secretory lysosome release is unique to CTL or whether natural killer (NK) and invariant NKT (iNKT) cytolytic cells of the innate immune system use a similar mechanism to focus perforin-bearing lysosome release. NK cells were conjugated with B-cell targets lacking major histocompatibility complex class I 721.221 cells, and iNKT cells were conjugated with glycolipid-pulsed CD1-bearing targets, then prepared for thin-section electron microscopy. High-resolution electron micrographs of the immunological synapse formed between NK and iNKT cytolytic cells with their targets revealed that in both NK and iNKT cells, the centrioles could be found associated (or 'docked') with the plasma membrane within the immunological synapse. Secretory clefts were visible within the synapses formed by both NK and iNKT cells, and secretory lysosomes were polarised along microtubules leading towards the docked centrosome. The Golgi apparatus and recycling endosomes were also polarised towards the centrosome at the plasma membrane within the synapse. These results reveal that, like CTLs of the adaptive immune system, the centrosomes of NK and iNKT cells (cytolytic cells of the innate immune system) direct secretory lysosomes to the immunological synapse. Morphologically, the

  11. Probing into the effects of a magnetic field on the electrode processes of iron in sulphuric acid solutions with dichromate based on the fundamental electrochemistry kinetics

    International Nuclear Information System (INIS)

    Lu Zhanpeng; Huang Delun; Yang Wu

    2005-01-01

    The effects of an applied magnetic field on the electrode processes of iron in sulphuric acid solutions with dichromate have been investigated by electrochemical measurements. Open circuit potentials, cathodic and anodic polarisation curves, values of polarisation resistance were measured in the presence or absence of a 0.4 T horizontal magnetic field (HMF). A potentiostatic polarisation plus magnetic field perturbation technique was used to study the effect of the magnetic field on open circuit corrosion. Cathodic reaction rates at open circuit potentials for iron in sulphuric acid solutions containing dichromate ions are controlled by both the electron-transfer process and the diffusion process. A magnetic field made the open circuit potential move in the positive direction, and changes of the open circuit potentials due to the magnetic field increase with increasing dichromate concentration. When iron was potentiostatically polarised at open circuit potentials in the absence of a magnetic field, a cathodic current was observed after a magnetic field was imposed. Such cathodic currents induced by the magnetic field increases with increasing dichromate concentration. The positive shifts of open circuit potential, the decrease of polarisation resistance, and the occurrence of cathodic currents induced by the magnetic field are caused by the accelerating effect of magnetic field on the cathodic diffusion process. Measured current densities showed lower, equal, or higher values in the presence of the magnetic field than those in the absence of a magnetic field at certain anodic potentials. This effect of the magnetic field is related to the contribution of the cathodic and anodic reactions to the measured current and the types of rate-determining steps for each reaction at certain potentials. The applied magnetic field significantly decreased the polarisation resistance. The experimental results in this paper are formulated based on the fundamental electrochemistry

  12. A case of spontaneous ventriculocisternostomy

    International Nuclear Information System (INIS)

    Yamane, Kanji; Yoshimoto, Hisanori; Harada, Kiyoshi; Uozumi, Tohru; Kuwabara, Satoshi.

    1983-01-01

    The authors experienced a case of spontaneous ventriculocisternostomy diagnosed by CT scan with metrizamide and Conray. Patient was 23-year-old male who had been in good health until one month before admission, when he began to have headache and tinnitus. He noticed bilateral visual acuity was decreased about one week before admission and vomiting appeared two days before admission. He was admitted to our hospital because of bilateral papilledema and remarkable hydrocephalus diagnosed by CT scan. On admission, no abnormal neurological signs except for bilateral papilledema were noted. Immediately, right ventricular drainage was performed. Pressure of the ventricle was over 300mmH 2 O and CSF was clear. PVG and PEG disclosed an another cavity behind the third ventricle, which was communicated with the third ventricle, and occlusion of aqueduct of Sylvius. Metrizamide CT scan and Conray CT scan showed a communication between this cavity and quadrigeminal and supracerebellar cisterns. On these neuroradiological findings, the diagnosis of obstructive hydrocephalus due to benign aqueduct stenosis accompanied with spontaneous ventriculocisternostomy was obtained. Spontaneous ventriculocisternostomy was noticed to produce arrest of hydrocephalus, but with our case, spontaneous regression of such symptoms did not appeared. By surgical ventriculocisternostomy (method by Torkildsen, Dandy, or Scarff), arrest of hydrocephalus was seen in about 50 to 70 per cent, which was the same results as those of spontaneous ventriculocisternostomy. It is concluded that VP shunt or VA shunt is thought to be better treatment of obstructive hydrocephalus than the various kinds of surgical ventriculocisternostomy. (J.P.N.)

  13. From neutrino physics to beam polarisation. A high precision story at the ILC

    International Nuclear Information System (INIS)

    Vormwald, Benedikt

    2014-03-01

    In this thesis, we investigate the experimental prospects of studying a supersymmetric model with bilinearly broken R parity at the International Linear Collider. In this model, neutrinos mix with the supersymmetric neutralinos such that neutrino properties can be probed by examining neutralino decays, which incorporate usually a lepton and a W/Z boson. As a study case, we focus on the determination of the atmospheric neutrino mixing angle θ 23 , which is accessible via the ratio of the neutralino branching ratios BR(χ 0 1 →Wμ)/BR(χ 0 1 →Wτ). A detailed simulation of the International Large Detector has been performed for all Standard Model backgrounds and for χ 0 1 -pair production within a simplified model. The study is based on ILC beam parameters according to the Technical Design Report for a center-of-mass energy of √(s)=500 GeV. From muonic χ 0 1 decays, we find that the χ 0 1 mass can be reconstructed with an uncertainty of δ(m χ 0 1 )=(40(stat.)+35(syst.)) MeV for an integrated luminosity of ∫Ldt=500 fb -1 . The ratio of branching ratios can be determined to a precision of δ(BR(χ 0 1 →Wμ)/BR(χ 0 1 →Wτ))=2.9%. Due to this, the atmospheric neutrino mixing angle can be deduced with a precision comparable to modern neutrino experiments. Thus, the ILC is capable to test whether bRPV SUSY is the mechanism of neutrino mass generation. As also shown in the bRPV SUSY study of this thesis, beam polarisation is an important parameter in physics analyses at the ILC. The beam polarisation is measured with two Compton polarimeters per electron/positron beam. In order to achieve the design goal of an envisaged precision of 0.25%, the detector nonlinearity of the used Cherenkov detectors has to be determined very precisely. Herein, the main source of nonlinearity is expected to originate from the involved photomultipliers. For this reason, a differential nonlinearity measurement as well as a linearisation method is developed. The working

  14. From neutrino physics to beam polarisation. A high precision story at the ILC

    Energy Technology Data Exchange (ETDEWEB)

    Vormwald, Benedikt

    2014-03-15

    In this thesis, we investigate the experimental prospects of studying a supersymmetric model with bilinearly broken R parity at the International Linear Collider. In this model, neutrinos mix with the supersymmetric neutralinos such that neutrino properties can be probed by examining neutralino decays, which incorporate usually a lepton and a W/Z boson. As a study case, we focus on the determination of the atmospheric neutrino mixing angle θ{sub 23}, which is accessible via the ratio of the neutralino branching ratios BR(χ{sup 0}{sub 1}→Wμ)/BR(χ{sup 0}{sub 1}→Wτ). A detailed simulation of the International Large Detector has been performed for all Standard Model backgrounds and for χ{sup 0}{sub 1}-pair production within a simplified model. The study is based on ILC beam parameters according to the Technical Design Report for a center-of-mass energy of √(s)=500 GeV. From muonic χ{sup 0}{sub 1} decays, we find that the χ{sup 0}{sub 1} mass can be reconstructed with an uncertainty of δ(m{sub χ{sup 0}{sub 1}})=(40(stat.)+35(syst.)) MeV for an integrated luminosity of ∫Ldt=500 fb{sup -1}. The ratio of branching ratios can be determined to a precision of δ(BR(χ{sup 0}{sub 1}→Wμ)/BR(χ{sup 0}{sub 1}→Wτ))=2.9%. Due to this, the atmospheric neutrino mixing angle can be deduced with a precision comparable to modern neutrino experiments. Thus, the ILC is capable to test whether bRPV SUSY is the mechanism of neutrino mass generation. As also shown in the bRPV SUSY study of this thesis, beam polarisation is an important parameter in physics analyses at the ILC. The beam polarisation is measured with two Compton polarimeters per electron/positron beam. In order to achieve the design goal of an envisaged precision of 0.25%, the detector nonlinearity of the used Cherenkov detectors has to be determined very precisely. Herein, the main source of nonlinearity is expected to originate from the involved photomultipliers. For this reason, a differential

  15. Measuring the polarisation anisotropy of the Cosmic Microwave Background with the QUBIC bolometric interferometer

    International Nuclear Information System (INIS)

    Bigot-Sazy, Marie-Anne

    2013-01-01

    The quest of B-mode polarisation of the cosmic background is one of the scientific priorities of the observational cosmology today. Observing the B-mode would be the most direct way to constrain the period of inflation. The detection of such a weak signal is however a real experimental challenge. In addition to a high statistical sensitivity (huge number of horns and bolometers required), future experiments will need an excellent quality of foreground removal and an unprecedented control of systematics. An important experimental effort aiming at the detection of the B-mode is in progress. The QUBIC instrument is one of the many experiments dedicated to the search of B-mode, it is based on a novel technology: bolometric interferometry. In this thesis, we explain the design of this instrument and we describe the different components. We will focus on the optical beam combiner, we will present a method which allows to study the effects of optical aberrations and of misalignments of the components of the combiner on the global sensitivity of the instrument. We will develop a new specific procedure of calibration: the self-calibration, specific to bolometric interferometry, which is based on the redundancy of baselines. The self-calibration relies on comparing all the redundant baselines with each others and permits to calibrate parameters that characterize completely the instrument at the same time for each channel. Finally, we will present the latest results of the simulation for the map-making with the instrument QUBIC and the estimation of the power spectra from the resulting maps. (author)

  16. Flow Friction or Spontaneous Ignition?

    Science.gov (United States)

    Stoltzfus, Joel M.; Gallus, Timothy D.; Sparks, Kyle

    2012-01-01

    "Flow friction," a proposed ignition mechanism in oxygen systems, has proved elusive in attempts at experimental verification. In this paper, the literature regarding flow friction is reviewed and the experimental verification attempts are briefly discussed. Another ignition mechanism, a form of spontaneous combustion, is proposed as an explanation for at least some of the fire events that have been attributed to flow friction in the literature. In addition, the results of a failure analysis performed at NASA Johnson Space Center White Sands Test Facility are presented, and the observations indicate that spontaneous combustion was the most likely cause of the fire in this 2000 psig (14 MPa) oxygen-enriched system.

  17. Spontaneous rupture of vaginal enterocele

    DEFF Research Database (Denmark)

    Svendsen, J H; Galatius, H; Hansen, P K

    1985-01-01

    Spontaneous rupture of an enterocele is a rare complication. Only 24 cases including the present case have been reported in the literature. The patients were elderly and had had at least one vaginal operation. The patients were remarkably unaffected symptomatically on admission.......Spontaneous rupture of an enterocele is a rare complication. Only 24 cases including the present case have been reported in the literature. The patients were elderly and had had at least one vaginal operation. The patients were remarkably unaffected symptomatically on admission....

  18. Spontaneous light emission in complex nanostructures

    Science.gov (United States)

    Blanco, L. A.; García de Abajo, F. J.

    2004-05-01

    The spontaneous emission of an excited atom surrounded by different materials is studied in the framework of a semiclassical approach, where the transition dipole moment acts as the source of the emission field. The emission in the presence of semiinfinite media, metallic nanorings, spheres, gratings, and other complex geometries is investigated. Strong emission enhancement effects are obtained in some of these geometries associated to the excitation of plasmons (e.g., in nanorings or spheres). Furthermore, the emission is shown to take place only along narrow angular distributions when the atom is located inside a low-index dielectric and near its planar surface, or when metallic nanogratings are employed at certain resonant wave lengths. In particular, axially symmetric gratings made of real silver metal are considered, and both emission rate enhancement and focused far-field emission are achieved simultaneously when the grating is decorated with further nanostructures.

  19. The behaviour of hydrogen-like atoms in an intense long-wave field

    International Nuclear Information System (INIS)

    Brodsky, A.M.

    1979-01-01

    The equations, which permit the calculation by means of regular operations of multiphoton photoionisation cross sections and the dynamic polarisabilities in an intense classical long-wave electromagnetic field, are considered for a hydrogen atom. The calculations have been performed for a circularly polarised field. A quantitative expression has been derived for the Lamb shift analogue, which can be verified experimentally. Within the framework of the problem the interaction at small distances is self-compensated and reduced to a constant potential. This conclusion is of general interest for the theory of strong interactions. (author)

  20. High Intensity Compton Scattering in a strong plane wave field of general form

    International Nuclear Information System (INIS)

    Hartin, A.; Moortgat-Pick, G.; Hamburg Univ.

    2011-06-01

    Photon emission by an electron embedded in a strong external field of general form is studied theoretically. The external field considered is a plane wave electromagnetic field of any number of components, period and polarisation. Exact, Volkov solutions of the Dirac equation with the 4-potential of the general external field are obtained. The photon emission is considered in the usual perturbation theory using the Volkov solutions to represent the electron. An expression for the transition probability of this process is obtained after the usual spin and polarisation sums, trace calculation and phase space integration. The final transition probability in the general case contains a single sum over contributions from external field photons, an integration over one of the phase space components and the Fourier transforms of the Volkov phases. The validity of the general expression is established by considering specific external fields. Known specific analytic forms of the transition probability are obtained after substitution of the 4-potential for a circularly polarised and constant crossed external field. As an example usage of the general result for the transition probability, the case of two circularly polarised external fields separated by a phase difference is studied both analytically and numerically. (orig.)

  1. High Intensity Compton Scattering in a strong plane wave field of general form

    Energy Technology Data Exchange (ETDEWEB)

    Hartin, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Moortgat-Pick, G. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik

    2011-06-15

    Photon emission by an electron embedded in a strong external field of general form is studied theoretically. The external field considered is a plane wave electromagnetic field of any number of components, period and polarisation. Exact, Volkov solutions of the Dirac equation with the 4-potential of the general external field are obtained. The photon emission is considered in the usual perturbation theory using the Volkov solutions to represent the electron. An expression for the transition probability of this process is obtained after the usual spin and polarisation sums, trace calculation and phase space integration. The final transition probability in the general case contains a single sum over contributions from external field photons, an integration over one of the phase space components and the Fourier transforms of the Volkov phases. The validity of the general expression is established by considering specific external fields. Known specific analytic forms of the transition probability are obtained after substitution of the 4-potential for a circularly polarised and constant crossed external field. As an example usage of the general result for the transition probability, the case of two circularly polarised external fields separated by a phase difference is studied both analytically and numerically. (orig.)

  2. Spontaneous breaking of supersymmetry and gauge invariance in supergravity

    Energy Technology Data Exchange (ETDEWEB)

    Sohnius, M. (European Organization for Nuclear Research, Geneva (Switzerland)); West, P. (King' s Coll., London (UK). Dept. of Mathematics)

    1982-08-09

    Using the new minimal auxillary fields of N = 1 supergravity it is found possible to construct a model of local supersymmetry which spontaneously breaks both supersymmetry and gauge invariance. The status of the cosmological constant resulting from this breaking is discussed.

  3. Spontaneous breaking of supersymmetry and gauge invariance in supergravity

    International Nuclear Information System (INIS)

    Sohnius, M.; West, P.

    1982-01-01

    Using the new minimal auxillary fields of N = 1 supergravity it is found possible to construct a model of local supersymmetry which spontaneously breaks both supersymmetry and gauge invariance. The status of the cosmological constant resulting from this breaking is discussed. (orig.)

  4. Nonextensive Entropy, Prior PDFs and Spontaneous Symmetry Breaking

    OpenAIRE

    Shafee, Fariel

    2008-01-01

    We show that using nonextensive entropy can lead to spontaneous symmetry breaking when a parameter changes its value from that applicable for a symmetric domain, as in field theory. We give the physical reasons and also show that even for symmetric Dirichlet priors, such a defnition of the entropy and the parameter value can lead to asymmetry when entropy is maximized.

  5. Galvanic manifestation of spontaneous coherence in the negative glow

    International Nuclear Information System (INIS)

    Zhechev, D; Parvanova, N

    2002-01-01

    Both the magnetic depolarization of the spontaneous emission from self-aligned states and the discharge galvanic reaction are measured simultaneously in a magnetic field. The observed galvanic peak is ascribed to magnetic destruction of self-aligned ensembles of atoms. This presents galvanic manifestation of coherent conductivity. (letter to the editor)

  6. Measurements of the neutral current e{sup {+-}}p cross sections using longitudinally polarised lepton beams at HERA II

    Energy Technology Data Exchange (ETDEWEB)

    Nikiforov, A.

    2007-01-18

    This thesis presents inclusive e{sup {+-}}p single and double differential cross sections for neutral current deep inelastic scattering measured as functions of the four-momentum transfer squared Q{sup 2} and the Bjorken variable x in interactions of longitudinally polarised leptons with unpolarised protons using the H1 detector at HERA II. An overview of the phenomenology of deep inelastic scattering is given and the experimental apparatus as well as the measurement and analysis procedures are described. The analysis is based on e{sup +}p data taken in 2003-04 and e{sup -}p data taken in 2005 at a centre-of-mass energy of {radical}(s)=318 GeV, with integrated luminosities of 47.6 pb{sup -1} and 98.4 pb{sup -1} for the e{sup +}p and e{sup -}p samples, respectively. The cross sections are measured in the range of 200polarisation e ects in neutral current interactions and to determine the structure function xF{sub 3}. The new HERA II data are combined together with previously published data from HERA I to determine the structure function xF{sub 3} with improved precision. Furthermore, this measurement is combined with the corresponding ZEUS measurement to provide the most accurate measurement of the interference structure function xF{sup {gamma}}{sup Z}{sub 3}, which is sensitive to the valence quark distributions down to low values of x. The data on polarised cross section asymmetries A{sup {+-}} are also combined with the ZEUS data. This leads to the first observation of parity violation in neutral current e{sup {+-}}p scattering at distances down to 10{sup -18} m. The data are well described by the Standard Model predictions. (orig.)

  7. Magnetic Field Structure in Relativistic Jets

    Directory of Open Access Journals (Sweden)

    Jermak Helen

    2013-12-01

    Full Text Available Relativistic jets are ubiquitous when considering an accreting black hole. Two of the most extreme examples of these systems are blazars and gamma-ray bursts (GRBs, the jets of which are thought to be threaded with a magnetic field of unknown structure. The systems are made up of a black hole accreting matter and producing, as a result, relativistic jets of plasma from the poles of the black hole. Both systems are viewed as point sources from Earth, making it impossible to spatially resolve the jet. In order to explore the structure of the magnetic field within the jet we take polarisation measurements with the RINGO polarimeters on the world’s largest fully autonomous, robotic optical telescope: The Liverpool Telescope. Using the polarisation degree and angle measured by the RINGO polarimeters it is possible to distinguish between global magnetic fields created in the central engine and random tangled magnetic fields produced locally in shocks. We also monitor blazar sources regularly during quiescence with periods of flaring monitored more intensively. Reported here are the early polarisation results for GRBs 060418 and 090102, along with future prospects for the Liverpool Telescope and the RINGO polarimeters.

  8. Simulating spontaneously generated coherence in a four-level atomic system

    International Nuclear Information System (INIS)

    Li Aijun; Gao Jinyue; Wu Jinhui; Wang Lei

    2005-01-01

    We study the spontaneous emission property of a four-level atomic system driven by two coherent fields. By numerical calculations in the bare state picture, we show that such interesting phenomena as extremely narrow peaks and spontaneous emission quenching can be realized, which are well understood by qualitative explanations in the partially and fully dressed state pictures. Especially, this coherently driven atomic system has two close-lying levels in the partially dressed state picture so that spontaneously generated coherence arises. Using our considered scheme it is feasible to carry out experiments based on spontaneously generated coherence because all rigorous requirements have been avoided in the bare state picture

  9. Polarisation of the ω meson in the pd→3Heω reaction at 1360 and 1450 MeV

    International Nuclear Information System (INIS)

    Schoenning, K.; Bargholtz, Chr.; Bashkanov, M.; Berlowski, M.; Bogoslawsky, D.; Calen, H.; Clement, H.; Demiroers, L.; Ekstroem, C.; Fransson, K.; Geren, L.; Gustafsson, L.; Hoeistad, B.; Ivanov, G.; Jacewicz, M.; Jiganov, E.; Johansson, T.; Keleta, S.; Khakimova, O.; Koch, I.

    2008-01-01

    The tensor polarisation of ω mesons produced in the pd→ 3 Heω reaction has been studied at two energies near threshold. The 3 He nuclei were detected in coincidence with the π 0 π + π - or π 0 γ decay products of the ω. In contrast to the case of φ-meson production, the ω mesons are found to be unpolarised. This brings into question the applicability of the Okubo-Zweig-Iizuka rule when comparing the production of vector mesons in low energy hadronic reactions

  10. Spontaneous Development of Moral Concepts

    Science.gov (United States)

    Siegal, M.

    1975-01-01

    Moral competence is more difficult to attain than scientific competence. Since language comprehension plays a central role in conceptual development, and moral language is difficult to learn, there is a common deficiency in moral conceptual development. This suggests a theory of non-spontaneous solutions to moral problems. (Author/MS)

  11. Spontaneous regression of pulmonary bullae

    International Nuclear Information System (INIS)

    Satoh, H.; Ishikawa, H.; Ohtsuka, M.; Sekizawa, K.

    2002-01-01

    The natural history of pulmonary bullae is often characterized by gradual, progressive enlargement. Spontaneous regression of bullae is, however, very rare. We report a case in which complete resolution of pulmonary bullae in the left upper lung occurred spontaneously. The management of pulmonary bullae is occasionally made difficult because of gradual progressive enlargement associated with abnormal pulmonary function. Some patients have multiple bulla in both lungs and/or have a history of pulmonary emphysema. Others have a giant bulla without emphysematous change in the lungs. Our present case had treated lung cancer with no evidence of local recurrence. He had no emphysematous change in lung function test and had no complaints, although the high resolution CT scan shows evidence of underlying minimal changes of emphysema. Ortin and Gurney presented three cases of spontaneous reduction in size of bulla. Interestingly, one of them had a marked decrease in the size of a bulla in association with thickening of the wall of the bulla, which was observed in our patient. This case we describe is of interest, not only because of the rarity with which regression of pulmonary bulla has been reported in the literature, but also because of the spontaneous improvements in the radiological picture in the absence of overt infection or tumor. Copyright (2002) Blackwell Science Pty Ltd

  12. Shell theorem for spontaneous emission

    DEFF Research Database (Denmark)

    Kristensen, Philip Trøst; Mortensen, Jakob Egeberg; Lodahl, Peter

    2013-01-01

    and therefore is given exactly by the dipole approximation theory. This surprising result is a spontaneous emission counterpart to the shell theorems of classical mechanics and electrostatics and provides insights into the physics of mesoscopic emitters as well as great simplifications in practical calculations....

  13. Silicosis with bilateral spontaneous pneumothorax

    Directory of Open Access Journals (Sweden)

    Fotedar Sanjay

    2010-01-01

    Full Text Available Presentation with simultaneous bilateral pneumothorax is uncommon and usually in the context of secondary spontaneous pneumothorax.The association of pneumothorax and silicosis is infrequent and most cases are unilateral. Bilateral pneumothorax in silicosis is very rare with just a few reports in medical literature.

  14. Prediction of Spontaneous Preterm Birth

    NARCIS (Netherlands)

    Dijkstra, Karolien

    2002-01-01

    Preterm birth is a leading cause of neonatal morbidity and mortality. It is a major goal in obstetrics to lower the incidence of spontaneous preterm birth (SPB) and related neonatal morbidity and mortality. One of the principal objectives is to discover early markers that would allow us to identify

  15. Spontaneous symmetry breaking, self-trapping, and Josephson oscillations

    CERN Document Server

    2013-01-01

    This volume collects a a number of contributions on spontaneous symmetry breaking. Current studies in this general field are going ahead at a full speed. The book present review chapters which give an overview on the major break throughs of recent years. It covers a number of different physical settings which are introduced when a nonlinearity is added to the underlying symmetric problems and its strength exceeds a certain critical value. The corresponding loss of symmetry, called spontaneous symmetry breaking, alias self-trapping into asymmetric states is extensively discussed in this book.

  16. Polarisation of major histocompatibility complex II host genotype with pathogenesis of European Brown Hare syndrome virus.

    Directory of Open Access Journals (Sweden)

    Christos Iacovakis

    Full Text Available A study was conducted in order to determine the occurrence of European Brown Hare Syndrome virus (EBHSV in Denmark and possible relation between disease pathogenesis and Major Histocompatibility Complex (MHC host genotype. Liver samples were examined from 170 brown hares (hunted, found sick or dead, collected between 2004 and 2009. Macroscopical and histopathological findings consistent with EBHS were detected in 24 (14.1% hares; 35 (20.6% had liver lesions not typical of the syndrome, 50 (29.4% had lesions in other tissues and 61 (35.9% had no lesions. Sixty five (38.2% of 170 samples were found to be EBHSV-positive (RT-PCR, VP60 gene. In order to investigate associations between viral pathogenesis and host genotype, variation within the exon 2 DQA gene of MHC was assessed. DQA exon 2 analysis revealed the occurrence of seven different alleles in Denmark. Consistent with other populations examined so far in Europe, observed heterozygosity of DQA (H o = 0.1180 was lower than expected (H e = 0.5835. The overall variation for both nucleotide and amino acid differences (2.9% and 14.9%, respectively were lower in Denmark than those assessed in other European countries (8.3% and 16.9%, respectively. Within the peptide binding region codons the number of nonsynonymous substitutions (dN was much higher than synonymous substitutions (dS, which would be expected for MHC alleles under balancing selection. Allele frequencies did not significantly differ between EBHSV-positive and -negative hares. However, allele Leeu-DQA*30 was detected in significantly higher (P = 0.000006 frequency among the positive hares found dead with severe histopathological lesions than among those found sick or apparently healthy. In contrast, the latter group was characterized by a higher frequency of the allele Leeu-DQA*14 as well as the proportion of heterozygous individuals (P = 0.000006 and P = 0.027. These data reveal a polarisation between EBHSV

  17. Polarisation parameter measurement in the proton-proton elastic scattering from 0.5 to 1.2 GeV

    International Nuclear Information System (INIS)

    Ducros, Yves

    1970-01-01

    The angular distribution of the polarisation parameter was measured in the proton-proton elastic - scattering at seven energies between 0.5 and 1.2 GeV. A polarized proton target was used. The results show a maximum of the polarisation parameter of 0.6, at 0.73 GeV. This maximum is due to the important increase of the total cross section between 0.6 and 0.73 GeV. At 1.2 GeV the angular distribution of the polarisation shows a minimum for a momentum transfer value of -1 (GeV/c) 2 . A phase shift analysis was done at 0.66 GeV, using all available experimental data at this energy. There is no evidence of a di-baryonic resonance in the 1 D 2 phase. (author) [fr

  18. Two-Polarisation Physical Model of Bowed Strings with Nonlinear Contact and Friction Forces, and Application to Gesture-Based Sound Synthesis

    Directory of Open Access Journals (Sweden)

    Charlotte Desvages

    2016-05-01

    Full Text Available Recent bowed string sound synthesis has relied on physical modelling techniques; the achievable realism and flexibility of gestural control are appealing, and the heavier computational cost becomes less significant as technology improves. A bowed string sound synthesis algorithm is designed, by simulating two-polarisation string motion, discretising the partial differential equations governing the string’s behaviour with the finite difference method. A globally energy balanced scheme is used, as a guarantee of numerical stability under highly nonlinear conditions. In one polarisation, a nonlinear contact model is used for the normal forces exerted by the dynamic bow hair, left hand fingers, and fingerboard. In the other polarisation, a force-velocity friction curve is used for the resulting tangential forces. The scheme update requires the solution of two nonlinear vector equations. The dynamic input parameters allow for simulating a wide range of gestures; some typical bow and left hand gestures are presented, along with synthetic sound and video demonstrations.

  19. A Case of Spontaneously Resolved Bilateral Primary Spontaneous Pneumothorax

    Directory of Open Access Journals (Sweden)

    Hasan Kahraman

    2014-03-01

    Full Text Available A condition of intrapleural air-space accumulation in individuals without any history of trauma or lung disease is called as primary spontaneous pneumothorax (PSP. Sixteen-years-old male patient admitted with complains of chest pain and dyspnea beginning 3 day ago. On physical examination, severity of breath sounds decreased on right side. Chest radiograph was taken and right-sided pneumothorax was detected and tube thoracostomy was inserted. Two months ago the patient referred to a doctor with similar complaints and physical examination and chest radiograph were reported as normal. The radiograph was retrospectively examined and bilateral PSP was detected. We presented the case duo to spontaneous recovery of bilateral PSP is seen very rarely and so contributes data to the literature. In patients admitted to the clinic with chest pain and shortness of breath, pneumothorax should be considered at differential diagnosis.

  20. Spontaneous Lorentz breaking at high energies

    International Nuclear Information System (INIS)

    Cheng, H.-C.; Luty, Markus A.; Mukohyama, Shinji; Thaler, Jesse

    2006-01-01

    Theories that spontaneously break Lorentz invariance also violate diffeomorphism symmetries, implying the existence of extra degrees of freedom and modifications of gravity. In the minimal model ('ghost condensation') with only a single extra degree of freedom at low energies, the scale of Lorentz violation cannot be larger than about M ∼ 100GeV due to an infrared instability in the gravity sector. We show that Lorentz symmetry can be broken at much higher scales in a non-minimal theory with additional degrees of freedom, in particular if Lorentz symmetry is broken by the vacuum expectation value of a vector field. This theory can be constructed by gauging ghost condensation, giving a systematic effective field theory description that allows us to estimate the size of all physical effects. We show that nonlinear effects become important for gravitational fields with strength Φ 1/2 ∼> g, where g is the gauge coupling, and we argue that the nonlinear dynamics is free from singularities. We then analyze the phenomenology of the model, including nonlinear dynamics and velocity-dependent effects. The strongest bounds on the gravitational sector come from either black hole accretion or direction-dependent gravitational forces, and imply that the scale of spontaneous Lorentz breaking is M ∼ 12 GeV, g 2 10 15 GeV). If the Lorentz breaking sector couples directly to matter, there is a spin-dependent inverse-square law force, which has a different angular dependence from the force mediated by the ghost condensate, providing a distinctive signature for this class of models

  1. Spontaneous Retropharyngeal Emphysema: A Case Report | Chi ...

    African Journals Online (AJOL)

    ... is a rare clinical condition in pediatric otolaryngology. The predominant symptoms are sore throat, odynophagia, dysphagia, and neck pain. Here, we report a case of spontaneous retropharyngeal emphysema. Keywords: Iatrogenic injury, retropharyngeal emphysema, spontaneous retropharyngeal emphysem, trauma ...

  2. Spontaneous wound dehiscence after penetrating keratoplasty

    Directory of Open Access Journals (Sweden)

    Alireza Foroutan

    2014-10-01

    Full Text Available Spontaneous wound separation may be developed even months after suture removal especially in the context of long-term corticosteroid therapy. A 68-year-old Caucasian woman presented to our cornea clinic with spontaneous wound dehiscence after her third penetrating keratoplasty (PKP which was performed three years ago. An Ahmed glaucoma valve (New World Medical, Ranchos Cucamonga, CA was inserted ten months after the third PKP, which successfully controlled intraocular pressure (IOP. At the examination, the last sutures were removed eight months ago and she was using flourometholone 0.1 % (Sina Darou, Tehran, Iran with a dose of once a day. There was one quadrant of wound dehiscence from 8 to 11 o`clock associated with anterior wound gape and severe corneal edema. Resuturing was performed for the patient. At the one month examination, the corneal edema was resolved and best corrected visual acuity was 20/200 mainly due to previous glaucomatous optic neuropathy. Caution about the prolonged use of corticosteroids is necessary. Topical immunosuppressives could be a promising choice in this field.

  3. Inclusive deep inelastic scattering at high Q{sup 2} with longitudinally polarised lepton beams at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Aaron, F.D. [National Institute for Physics and Nuclear Engineering (NIPNE), Bucharest (Romania); Bucharest Univ. (Romania). Faculty of Physics; Alexa, C. [National Institute for Physics and Nuclear Engineering (NIPNE), Bucharest (Romania); Andreev, V. [Lebedev Physical Institute, Moscow (RU)] (and others)

    2012-06-15

    Inclusive e{sup {+-}}p single and double differential cross sections for neutral and charged current deep inelastic scattering processes are measured with the H1 detector at HERA. The data were taken at a centre-of-mass energy of {radical}(s)=319 GeV with a total integrated luminosity of 333.7 pb{sup -1} shared between two lepton beam charges and two longitudinal lepton polarisation modes. The differential cross sections are measured in the range of negative four-momentum transfer squared, Q{sup 2}, between 60 and 50000 GeV{sup 2}, and Bjorken x between 0.0008 and 0.65. The measurements are combined with earlier published unpolarised H1 data to improve statistical precision and used to determine the structure function xF{sup {gamma}}{sup Z}{sub 3}. A measurement of the neutral current parity violating structure function F{sup {gamma}}{sup Z}{sub 2} is presented for the first time. The polarisation dependence of the charged current total cross section is also measured. The new measurements are well described by a next-to-leading order QCD fit based on all published H1 inclusive cross section data which are used to extract the parton distribution functions of the proton.

  4. Measurement of W boson polarisations and CP-violating triple gauge couplings from $W^{+}W^{-}$ production at LEP

    CERN Document Server

    Abbiendi, G.; Ainsley, C.; Akesson, P.F.; Alexander, G.; Allison, John; Anderson, K.J.; Arcelli, S.; Asai, S.; Ashby, S.F.; Axen, D.; Azuelos, G.; Bailey, I.; Ball, A.H.; Barberio, E.; Barlow, Roger J.; Baumann, S.; Behnke, T.; Bell, Kenneth Watson; Bella, G.; Bellerive, A.; Benelli, G.; Bentvelsen, S.; Bethke, S.; Biebel, O.; Bloodworth, I.J.; Boeriu, O.; Bock, P.; Bohme, J.; Bonacorsi, D.; Boutemeur, M.; Braibant, S.; Bright-Thomas, P.; Brigliadori, L.; Brown, Robert M.; Burckhart, H.J.; Cammin, J.; Capiluppi, P.; Carnegie, R.K.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, David G.; Clarke, P.E.L.; Clay, E.; Cohen, I.; Cooke, O.C.; Couchman, J.; Couyoumtzelis, C.; Coxe, R.L.; Csilling, A.; Cuffiani, M.; Dado, S.; Dallavalle, G.Marco; Dallison, S.; de Roeck, A.; de Wolf, E.; Dervan, P.; Desch, K.; Dienes, B.; Dixit, M.S.; Donkers, M.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Estabrooks, P.G.; Etzion, E.; Fabbri, F.; Fanti, M.; Feld, L.; Ferrari, P.; Fiedler, F.; Fleck, I.; Ford, M.; Frey, A.; Furtjes, A.; Futyan, D.I.; Gagnon, P.; Gary, J.W.; Gaycken, G.; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Glenzinski, D.; Goldberg, J.; Grandi, C.; Graham, K.; Gross, E.; Grunhaus, J.; Gruwe, M.; Gunther, P.O.; Hajdu, C.; Hanson, G.G.; Hansroul, M.; Hapke, M.; Harder, K.; Harel, A.; Harin-Dirac, M.; Hauke, A.; Hauschild, M.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Hensel, C.; Herten, G.; Heuer, R.D.; Hill, J.C.; Hocker, James Andrew; Hoffman, Kara Dion; Homer, R.J.; Honma, A.K.; Horvath, D.; Hossain, K.R.; Howard, R.; Huntemeyer, P.; Igo-Kemenes, P.; Ishii, K.; Jacob, F.R.; Jawahery, A.; Jeremie, H.; Jones, C.R.; Jovanovic, P.; Junk, T.R.; Kanaya, N.; Kanzaki, J.; Karapetian, G.; Karlen, D.; Kartvelishvili, V.; Kawagoe, K.; Kawamoto, T.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Kim, D.H.; Klein, K.; Klier, A.; Kluth, S.; Kobayashi, T.; Kobel, M.; Kokott, T.P.; Komamiya, S.; Kowalewski, Robert V.; Kress, T.; Krieger, P.; von Krogh, J.; Kuhl, T.; Kupper, M.; Kyberd, P.; Lafferty, G.D.; Landsman, H.; Lanske, D.; Lawson, I.; Layter, J.G.; Leins, A.; Lellouch, D.; Letts, J.; Levinson, L.; Liebisch, R.; Lillich, J.; List, B.; Littlewood, C.; Lloyd, A.W.; Lloyd, S.L.; Loebinger, F.K.; Long, G.D.; Losty, M.J.; Lu, J.; Ludwig, J.; Macchiolo, A.; Macpherson, A.; Mader, W.; Marcellini, S.; Marchant, T.E.; Martin, A.J.; Martin, J.P.; Martinez, G.; Mashimo, T.; Mattig, Peter; McDonald, W.John; McKenna, J.; McMahon, T.J.; McPherson, R.A.; Meijers, F.; Mendez-Lorenzo, P.; Menges, W.; Merritt, F.S.; Mes, H.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D.J.; Mohr, W.; Montanari, A.; Mori, T.; Nagai, K.; Nakamura, I.; Neal, H.A.; Nisius, R.; O'Neale, S.W.; Oakham, F.G.; Odorici, F.; Ogren, H.O.; Oh, A.; Okpara, A.; Oreglia, M.J.; Orito, S.; Pasztor, G.; Pater, J.R.; Patrick, G.N.; Patt, J.; Pfeifenschneider, P.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Poli, B.; Polok, J.; Pooth, O.; Przybycien, M.; Quadt, A.; Rembser, C.; Renkel, P.; Rick, H.; Rodning, N.; Roney, J.M.; Rosati, S.; Roscoe, K.; Rossi, A.M.; Rozen, Y.; Runge, K.; Runolfsson, O.; Rust, D.R.; Sachs, K.; Saeki, T.; Sahr, O.; Sarkisyan, E.K.G.; Sbarra, C.; Schaile, A.D.; Schaile, O.; Scharff-Hansen, P.; Schroder, Matthias; Schumacher, M.; Schwick, C.; Scott, W.G.; Seuster, R.; Shears, T.G.; Shen, B.C.; Shepherd-Themistocleous, C.H.; Sherwood, P.; Siroli, G.P.; Skuja, A.; Smith, A.M.; Snow, G.A.; Sobie, R.; Soldner-Rembold, S.; Spagnolo, S.; Sproston, M.; Stahl, A.; Stephens, K.; Stoll, K.; Strom, David M.; Strohmer, R.; Stumpf, L.; Surrow, B.; Talbot, S.D.; Tarem, S.; Taylor, R.J.; Teuscher, R.; Thiergen, M.; Thomas, J.; Thomson, M.A.; Torrence, E.; Towers, S.; Toya, D.; Trefzger, T.; Trigger, I.; Trocsanyi, Z.; Tsur, E.; Turner-Watson, M.F.; Ueda, I.; Vachon, B.; Vannerem, P.; Verzocchi, M.; Voss, H.; Vossebeld, J.; Waller, D.; Ward, C.P.; Ward, D.R.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wengler, T.; Wermes, N.; Wetterling, D.; White, J.S.; Wilson, G.W.; Wilson, J.A.; Wyatt, T.R.; Yamashita, S.; Zacek, V.; Zer-Zion, D.

    2001-01-01

    Measurements are presented of the polarisation of W+W- boson pairs produced in e+e- collisions, and of CP-violating WWZ and WWGamma trilinear gauge couplings. The data were recorded by the OPAL experiment at LEP during 1998, where a total integrated luminosity of 183 pb^-1 was obtained at a centre-of-mass energy of 189 GeV. The measurements are performed through a spin density matrix analysis of the W boson decay products. The fraction of W bosons produced with longitudinal polarisation was found to be sigma_L/sigma_total = (21.0 +- 3.3 +- 1.6)% where the first error is statistical and the second systematic. The joint W boson pair production fractions were found to be sigma_TT/sigma_total = (78.1 +- 9.0 +- 3.2) %, sigma_LL/sigma_total = (20.1 +- 7.2 +- 1.8) % and sigma_TL/sigma_total = (1.8 +- 14.7 +- 3.8) %. In the CP-violating trilinear gauge coupling sector we find kappa_z = -0.20 +0.10 -0.07, g^z_4 = -0.02 +0.32 -0.33 and lambda_z = -0.18 +0.24 -0.16, where errors include both statistical and systematic u...

  5. Measurement of high-Q2 neutral current cross-sections with longitudinally polarised positrons with the ZEUS detector

    International Nuclear Information System (INIS)

    Stewart, Trevor P.

    2012-07-01

    The cross sections for neutral current (NC) deep inelastic scattering (DIS) in e + p collisions with a longitudinally polarised positron beam are measured at high momentum transfer squared (Q 2 >185 GeV 2 ) at the ZEUS detector at HERA. The HERA accelerator provides e ± p collisions at a centre-of-mass energy of 318 GeV, which allows the weak contribution to the NC process to be studied at high Q 2 . The measurements are based on a data sample with an integrated luminosity of 135.5 pb -1 collected with the ZEUS detector in 2006 and 2007. The single differential NC cross sections dσ/dQ 2 , dσ/dx and dσ/dy and the reduced cross section σ are measured. The structure function xF 3 is determined by combining the e + p NC reduced cross sections with the previously measured e - p measurements. The interference structure function xF 3 γZ is extracted at Q 2 =1500 GeV 2 . The cross-section asymmetry between the positive and negative polarisation of the positron beam is measured and the parity violation effects of the electroweak interaction are observed. The predictions of the Standard Model of particle physics agree well with the measurements. (orig.)

  6. Measurement of charged current deep inelastic scattering cross sections with a longitudinally polarised electron beam at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Chekanov, S.; Derrick, M.; Magill, S. [Argonne National Laboratory, IL (US)] (and others)

    2008-12-15

    Measurements of the cross sections for charged current deep inelastic scattering in e{sup -}p collisions with longitudinally polarised electron beams are presented. The measurements are based on a data sample with an integrated luminosity of 175 pb{sup -1} collected with the ZEUS detector at HERA at a centre-of-mass energy of 318 GeV. The total cross section is given for positively and negatively polarised electron beams. The differential cross-sections d{sigma}/dQ{sup 2}, d{sigma}/dx and d{sigma}/dy are presented for Q{sup 2}>200 GeV{sup 2}. The double-differential cross-section d{sup 2}{sigma}/dxdQ{sup 2} is presented in the kinematic range 280

  7. Measurement of high-Q{sup 2} neutral current cross-sections with longitudinally polarised positrons with the ZEUS detector

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Trevor P.

    2012-07-15

    The cross sections for neutral current (NC) deep inelastic scattering (DIS) in e{sup +}p collisions with a longitudinally polarised positron beam are measured at high momentum transfer squared (Q{sup 2}>185 GeV{sup 2}) at the ZEUS detector at HERA. The HERA accelerator provides e{sup {+-}}p collisions at a centre-of-mass energy of 318 GeV, which allows the weak contribution to the NC process to be studied at high Q{sup 2}. The measurements are based on a data sample with an integrated luminosity of 135.5 pb{sup -1} collected with the ZEUS detector in 2006 and 2007. The single differential NC cross sections d{sigma}/dQ{sup 2}, d{sigma}/dx and d{sigma}/dy and the reduced cross section {sigma} are measured. The structure function xF{sub 3} is determined by combining the e{sup +}p NC reduced cross sections with the previously measured e{sup -}p measurements. The interference structure function xF{sub 3}{sup {gamma}Z} is extracted at Q{sup 2}=1500 GeV{sup 2}. The cross-section asymmetry between the positive and negative polarisation of the positron beam is measured and the parity violation effects of the electroweak interaction are observed. The predictions of the Standard Model of particle physics agree well with the measurements. (orig.)

  8. Spontaneous Hall effect in a chiral p-wave superconductor

    Science.gov (United States)

    Furusaki, Akira; Matsumoto, Masashige; Sigrist, Manfred

    2001-08-01

    In a chiral superconductor with broken time-reversal symmetry a ``spontaneous Hall effect'' may be observed. We analyze this phenomenon by taking into account the surface properties of a chiral superconductor. We identify two main contributions to the spontaneous Hall effect. One contribution originates from the Bernoulli (or Lorentz) force due to spontaneous currents running along the surfaces of the superconductor. The other contribution has a topological origin and is related to the intrinsic angular momentum of Cooper pairs. The latter can be described in terms of a Chern-Simons-like term in the low-energy field theory of the superconductor and has some similarities with the quantum Hall effect. The spontaneous Hall effect in a chiral superconductor is, however, nonuniversal. Our analysis is based on three approaches to the problem: a self-consistent solution of the Bogoliubov-de Gennes equation, a generalized Ginzburg-Landau theory, and a hydrodynamic formulation. All three methods consistently lead to the same conclusion that the spontaneous Hall resistance of a two-dimensional superconducting Hall bar is of order h/(ekFλ)2, where kF is the Fermi wave vector and λ is the London penetration depth; the Hall resistance is substantially suppressed from a quantum unit of resistance. Experimental issues in measuring this effect are briefly discussed.

  9. Spontaneous Rotational Inversion in Phycomyces

    KAUST Repository

    Goriely, Alain

    2011-03-01

    The filamentary fungus Phycomyces blakesleeanus undergoes a series of remarkable transitions during aerial growth. During what is known as the stagea IV growth phase, the fungus extends while rotating in a counterclockwise manner when viewed from above (stagea IVa) and then, while continuing to grow, spontaneously reverses to a clockwise rotation (stagea IVb). This phase lasts for 24-48Ah and is sometimes followed by yet another reversal (stageAIVc) before the overall growth ends. Here, we propose a continuum mechanical model of this entire process using nonlinear, anisotropic, elasticity and show how helical anisotropy associated with the cell wall structure can induce spontaneous rotation and, under appropriate circumstances, the observed reversal of rotational handedness. © 2011 American Physical Society.

  10. Management of intractable spontaneous epistaxis

    Science.gov (United States)

    Rudmik, Luke

    2012-01-01

    Background: Epistaxis is a common otolaryngology emergency and is often controlled with first-line interventions such as cautery, hemostatic agents, or anterior nasal packing. A subset of patients will continue to bleed and require more aggressive therapy. Methods: Intractable spontaneous epistaxis was traditionally managed with posterior nasal packing and prolonged hospital admission. In an effort to reduce patient morbidity and shorten hospital stay, surgical and endovascular techniques have gained popularity. A literature review was conducted. Results: Transnasal endoscopic sphenopalatine artery ligation and arterial embolization provide excellent control rates but the decision to choose one over the other can be challenging. The role of transnasal endoscopic anterior ethmoid artery ligation is unclear but may be considered in certain cases when bleeding localizes to the ethmoid region. Conclusion: This article will focus on the management of intractable spontaneous epistaxis and discuss the role of endoscopic arterial ligation and embolization as it pertains to this challenging clinical scenario. PMID:22391084

  11. Spontaneous Broken Local Conformal Symmetry and Dark Energy Candidate

    International Nuclear Information System (INIS)

    Liu, Lu-Xin

    2013-01-01

    The local conformal symmetry is spontaneously broken down to the Local Lorentz invariance symmetry through the approach of nonlinear realization. The resulting effective Lagrangian, in the unitary gauge, describes a cosmological vector field non-minimally coupling to the gravitational field. As a result of the Higgs mechanism, the vector field absorbs the dilaton and becomes massive, but with an independent energy scale. The Proca type vector field can be modelled as dark energy candidate. The possibility that it further triggers Lorentz symmetry violation is also pointed out

  12. Spontaneous esophageal-pleural fistula

    OpenAIRE

    Vyas, Sameer; Prakash, Mahesh; Kaman, Lileshwar; Bhardwaj, Nidhi; Khandelwal, Niranjan

    2011-01-01

    Spontaneous esophageal-pleural fistula (EPF) is a rare entity. We describe a case in a middle-aged female who presented with severe retrosternal chest pain and shortness of breadth. Chest computed tomography showed right EPF and hydropneumothorax. She was managed conservatively keeping the chest tube drainage and performing feeding jejunostomy. A brief review of the imaging finding and management of EPF is discussed.

  13. Spontaneous esophageal-pleural fistula.

    Science.gov (United States)

    Vyas, Sameer; Prakash, Mahesh; Kaman, Lileshwar; Bhardwaj, Nidhi; Khandelwal, Niranjan

    2011-10-01

    Spontaneous esophageal-pleural fistula (EPF) is a rare entity. We describe a case in a middle-aged female who presented with severe retrosternal chest pain and shortness of breadth. Chest computed tomography showed right EPF and hydropneumothorax. She was managed conservatively keeping the chest tube drainage and performing feeding jejunostomy. A brief review of the imaging finding and management of EPF is discussed.

  14. Spontaneous esophageal-pleural fistula

    Directory of Open Access Journals (Sweden)

    Sameer Vyas

    2011-01-01

    Full Text Available Spontaneous esophageal-pleural fistula (EPF is a rare entity. We describe a case in a middle-aged female who presented with severe retrosternal chest pain and shortness of breadth. Chest computed tomography showed right EPF and hydropneumothorax. She was managed conservatively keeping the chest tube drainage and performing feeding jejunostomy. A brief review of the imaging finding and management of EPF is discussed.

  15. Spontaneous acute spinal subdural hematoma: spontaneous recovery from severe paraparesis--case report and review.

    Science.gov (United States)

    Payer, Michael; Agosti, Reto

    2010-11-01

    Spontaneous idiopathic acute spinal subdural hematomas are highly exceptional. Neurological symptoms are usually severe, and rapid diagnosis with MRI is mandatory. Surgical evacuation has frequently been used therapeutically; however, spontaneous recovery in mild cases has also been reported. We present a case of spontaneous recovery from severe paraparesis after spontaneous acute SSDH, and review the English-speaking literature.

  16. Spontaneous fission of 259Md

    International Nuclear Information System (INIS)

    Hulet, E.K.; Wild, J.F.; Lougheed, R.W.; Baisden, P.A.; Landrum, J.H.; Dougan, R.J.; Mustafa, M.; Ghiorso, A.; Nitschke, J.M.

    1979-01-01

    The mass and kinetic energy distributions of fission fragments from the spontaneous fission of th newly discovered nuclide 259 Md were obtained. 259 Md was identified as the E. C. daughter of 259 No, and was found to decay entirely (> 95%) by spontaneous fission with a 95-min half-life. From the kinetic energies measured for 397 pairs of coincident fragments, a mass distribution was derived that is symmetric with sigma = 13 amu. 259 Md, together with 258 Fm and 259 Fm, form a select group of three nuclides whose mass division in spontaneous fission is highly symmetric. Unlike the total-kinetic-energy (TKE) distributions of 258 Fm and 259 Fm, which peak at approx. = to 240 MeV, this distribution for 259 Md is broad and is 50 MeV lower in energy. Analysis of the mass and energy distributions shows that events near mass symmetry also exhibit a broad TKE distribution, with one-third of the symmetric events having TKEs less than 200 MeV. The associated of low TKEs with symmetric mass division in the fission of very heavy actinides is anomalous and inconsistent with theories based upon the emergence of fragment shells near the scission point. Either three-body fragmentation or peculiar fragment shapes are assumed as the cause for the large consumption of Coulomb energy observed for a significant fraction of symmetric fissions in 259 Md. 6 figures

  17. Spontaneous Splenic Rupture in Melanoma

    Directory of Open Access Journals (Sweden)

    Hadi Mirfazaelian

    2014-01-01

    Full Text Available Spontaneous rupture of spleen due to malignant melanoma is a rare situation, with only a few case reports in the literature. This study reports a previously healthy, 30-year-old man who came with chief complaint of acute abdominal pain to emergency room. On physical examination, abdominal tenderness and guarding were detected to be coincident with hypotension. Ultrasonography revealed mild splenomegaly with moderate free fluid in abdominopelvic cavity. Considering acute abdominal pain and hemodynamic instability, he underwent splenectomy with splenic rupture as the source of bleeding. Histologic examination showed diffuse infiltration by tumor. Immunohistochemical study (positive for S100, HMB45, and vimentin and negative for CK, CD10, CK20, CK7, CD30, LCA, EMA, and chromogranin confirmed metastatic malignant melanoma. On further questioning, there was a past history of a nasal dark skin lesion which was removed two years ago with no pathologic examination. Spontaneous (nontraumatic rupture of spleen is an uncommon situation and it happens very rarely due to neoplastic metastasis. Metastasis of malignant melanoma is one of the rare causes of the spontaneous rupture of spleen.

  18. Spontaneous Symmetry Breaking and Nambu-Goldstone Bosons in Quantum Many-Body Systems

    Czech Academy of Sciences Publication Activity Database

    Brauner, Tomáš

    2010-01-01

    Roč. 2, č. 2 (2010), s. 609-657 ISSN 2073-8994 Institutional support: RVO:61389005 Keywords : spontaneous symmetry breaking * Nambu-Goldstone bosons * effective field theory Subject RIV: BE - Theoretical Physics

  19. Quantum fluctuations and spontaneous compactification of eleven-dimensional gravity

    International Nuclear Information System (INIS)

    Nguen Van Hieu.

    1985-01-01

    The reduction of the eleven-dimensional pure gravity to the field theory in the four-dimensional Minkowski space-time by means of the spontaneous compactification of the extra dimensions is investigated. The contribution of the quantum fluctuations of the eleven-dimen-- sonal second rank symmetric tensor field to the curvatures of the space-time and the compactified space of the extra dimensions are calculated in the one-loop approximation. It is shown that there exist the values of the cosmological constant for which tachions are absent. As a result, self-consistent quantum field theory is obtained in spontaneous compactified Minkowski space M 4 xS 7 ,is where M 4 is Minkowski space-time, and S 7 is seven-dimensional sphere

  20. [Social crisis, spontaneous groups and group order].

    Science.gov (United States)

    Edelman, Lucila; Kordon, Diana

    2002-12-01

    Argentina has gone through very difficult times during the last years and, in particularly, new kinds of social practices have emerged in order to cope with the crisis. This situation demands and urges a new type of reflection upon the double role of groups, as tools to transform reality and as a way to elaborate those processes regarding subjectivity. In this paper we analyse some topics regarding the groupal field (considering spontaneous groups as well as groupal devices that allow to elaborate the crisis). We consider social bond to be the condition of possibility for the existence of the psyche and of time continuity, and that it also makes possible personal and social elaboration of trauma, crisis and social catastrophe. We develop some aspects of an specific device (the reflection group), which we have already depicted in another moment, showing it's usefulness to cope with social crisis and to promote the subjective elaboration of crisis.

  1. Spontaneous magnetoelastic effects in gadolinium compounds

    International Nuclear Information System (INIS)

    Lindbaum, A.; Rotter, M.

    2002-01-01

    Full text: This poster is a short summary of a recently published handbook chapter, where the spontaneous magnetoelastic effects in Gd compounds are reviewed showing that the strain dependence of the magnetic exchange interactions leads to significant effects. These effects are equal in magnitude to well established single ion contributions in other rare earth compounds with non vanishing orbital momentum (coming from the strain dependence of the crystal field). In some cases the exchange contribution can produce giant magnetostriction (GMS) or induce structural phase transitions. In order to extract the influence of the Gd- Gd exchange interactions, we consider only Gd compounds with partner elements showing no or only weak induced magnetic moments. The current status of the theory is presented and compared to measurements performed by temperature dependent x-ray diffraction and results of dilatometric measurements. (author)

  2. Spontaneous Gamma Activity in Schizophrenia.

    Science.gov (United States)

    Hirano, Yoji; Oribe, Naoya; Kanba, Shigenobu; Onitsuka, Toshiaki; Nestor, Paul G; Spencer, Kevin M

    2015-08-01

    A major goal of translational neuroscience is to identify neural circuit abnormalities in neuropsychiatric disorders that can be studied in animal models to facilitate the development of new treatments. Oscillations in the gamma band (30-100 Hz) of the electroencephalogram have received considerable interest as the basic mechanisms underlying these oscillations are understood, and gamma abnormalities have been found in schizophrenia (SZ). Animal models of SZ based on hypofunction of the N-methyl-d-aspartate receptor (NMDAR) demonstrate increased spontaneous broadband gamma power, but this phenomenon has not been identified clearly in patients with SZ. To examine spontaneous gamma power and its relationship to evoked gamma oscillations in the auditory cortex of patients with SZ. We performed a cross-sectional study including 24 patients with chronic SZ and 24 matched healthy control participants at the Veterans Affairs Boston Healthcare System from January 1, 2009, through December 31, 2012. Electroencephalograms were obtained during auditory steady-state stimulation at multiple frequencies (20, 30, and 40 Hz) and during a resting state in 18 participants in each group. Electroencephalographic activity in the auditory cortex was estimated using dipole source localization. Auditory steady-state response (ASSR) measures included the phase-locking factor and evoked power. Spontaneous gamma power was measured as induced (non-phase-locked) gamma power in the ASSR data and as total gamma power in the resting-state data. The ASSR phase-locking factor was reduced significantly in patients with SZ compared with controls for the 40-Hz stimulation (mean [SD], 0.075 [0.028] vs 0.113 [0.065]; F1,46 = 6.79 [P = .012]) but not the 20- or the 30-Hz stimulation (0.042 [0.038] vs 0.043 [0.034]; F1,46 = 0.006 [P = .938] and 0.084 [0.040] vs 0.098 [0.050]; F1,46 = 1.605 [P = .212], respectively), repeating previous findings. The mean [SD] broadband-induced (30

  3. Do static atoms outside a Schwarzschild black hole spontaneously excite?

    International Nuclear Information System (INIS)

    Yu Hongwei; Zhou Wenting

    2007-01-01

    The spontaneous excitation of a two-level atom held static outside a four dimensional Schwarzschild black hole and in interaction with a massless scalar field in the Boulware, Unruh, and Hartle-Hawking vacuums is investigated, and the contributions of the vacuum fluctuations and radiation reaction to the rate of change of the mean atomic energy are calculated separately. We find that, for the Boulware vacuum, the spontaneous excitation does not occur and the ground-state atoms are stable, while the spontaneous emission rate for excited atoms in the Boulware vacuum, which is well behaved at the event horizon, is not the same as that in the usual Minkowski vacuum. However, for both the Unruh vacuum and the Hartle-Hawking vacuum, our results show that the atom would spontaneously excite, as if there were an outgoing thermal flux of radiation or as if it were in a thermal bath of radiation at a proper temperature which reduces to the Hawking temperature in the spatial asymptotic region, depending on whether the scalar field is in the Unruh or Hartle-Hawking vacuum

  4. Development and construction of a large TPC prototype for the ILC and study of τ polarisation in τ decays with the ILD detector

    International Nuclear Information System (INIS)

    Schade, Peter

    2009-11-01

    This thesis presents two studies which have been made in the framework of the detector development for the International Large Detector (ILD). In the preparation phase for the ILD, prototype studies are performed to develop and optimise the sub-detector technologies which will come into operation. Complementary to these hardware studies, expected physics scenarios are being investigated in full detector simulations. These simulations demonstrate the physics potential of the detector concept and are a benchmark for the detector and the accelerator design. The first part of this thesis gives an introduction to the physics questions addressed to the ILC. Also, the machine and the ILD detector concept are presented. The second part is dedicated to the development and the construction to a large Time Projection Chamber (TPC) prototype (LP). A TPC is foreseen as one of ILD's sub-detectors and shall measure the trajectories of charged particles with an accuracy unprecedented by TPCs operated before. The new prototype offers an infrastructure for the development of modern TPC readout structures which can fulfil the required criteria. Before construction, the design plans of the LP have been optimised for a low material budget of the structure and a very homogeneous drift field. During the manufacturing of the LP, experience with construction techniques has been gained for the construction of the ILD TPC. The third part deals with a simulation study for a polarisation measurement of τ leptons in the process e + e - → τ 1 τ 1 → χ 1 0 χ 1 0 ττ. Here, the τ 1 is the supersymmetric partner of the τ lepton. This simulation study shows the feasibility of the measurement in the chosen SUSY scenario and estimates the accuracy to be expected. Both studies address in particular the track reconstruction capabilities of the ILD detector. Conclusions of the discussed studies and an outlook are presented in part IV. (orig.)

  5. A first measurement of the charged current DIS cross sections with longitudinally polarised electrons in the H1 experiment at HERA

    International Nuclear Information System (INIS)

    Antunovic, B.

    2007-01-01

    The analysis presented in this thesis is based on data from electron-proton collisions with longitudinally polarised electron beams at a centre-of-mass energy of √(s)=319 GeV. The data were taken with the H1 detector at the HERA collider in the year 2005 corresponding to two polarisation states: a left-handed electron polarisation of -27% and a right-handed electron polarisation of +37%, corresponding to integrated luminosities of 68.6 pb -1 and 29.6 pb -1 , respectively. The inclusive total deep inelastic charged current cross section and the differential cross sections are measured for both helicities in the kinematic domain Q 2 >400 GeV 2 and y cc 2 has been performed at the H1 experiment for the first time. The measurements are well described by the theoretical expectations based on parton distributions derived from inclusive neutral current measurements in H1, and are in agreement with published data from the ZEUS (e ± p) and CCFR (anti ν μ Fe) experiments. (orig.)

  6. Polarisation observations of VY Canis Majoris H2O 5 32-441 620.701 GHz maser emission with HIFI

    NARCIS (Netherlands)

    Harwit, M.; Houde, M.; Sonnentrucker, P.; Boogert, A. C. A.; Cernicharo, J.; De Beck, E.; Decin, L.; Henkel, C.; Higgins, R. D.; Jellema, W.; Kraus, A.; McCoey, C.; Melnick, G. J.; Menten, K. M.; Risacher, C.; Teyssier, D.; Vaillancourt, J. E.; Alcolea, J.; Bujarrabal, V.; Dominik, C.; Justtanont, K.; de Koter, A.; Marston, A.P.; Olofsson, H.; Planesas, P.; Schmidt, M.; Schöier, F. L.; Szczerba, R.; Waters, L.B.F.M.

    2010-01-01

    Water vapour maser emission from evolved oxygen-rich stars remains poorly understood. Additional observations, including polarisation studies and simultaneous observation of different maser transitions may ultimately lead to greater insight. Aims. We have aimed to elucidate the nature and structure

  7. Polarisation observations of VY Canis Majoris H2O 5(32)-4(41) 620.701 GHz maser emission with HIFI

    NARCIS (Netherlands)

    Harwit, M.; Houde, M.; Sonnentrucker, P.; Boogert, A. C. A.; Cernicharo, J.; de Beck, E.; Decin, L.; Henkel, C.; Higgins, R. D.; Jellema, W.; Kraus, A.; McCoey, C.; Melnick, G. J.; Menten, K. M.; Risacher, C.; Teyssier, D.; Vaillancourt, J. E.; Alcolea, J.; Bujarrabal, V.; Dominik, C.; Justtanont, K.; de Koter, A.; Marston, A. P.; Olofsson, H.; Planesas, P.; Schmidt, M.; Schöier, F. L.; Szczerba, R.; Waters, L. B. F. M.

    2010-01-01

    Context. Water vapour maser emission from evolved oxygen-rich stars remains poorly understood. Additional observations, including polarisation studies and simultaneous observation of different maser transitions may ultimately lead to greater insight. Aims. We have aimed to elucidate the nature and

  8. Numerical analysis of the effect of the TEM00 radiation mode polarisation on the cut shape in laser cutting of thick metal sheets

    International Nuclear Information System (INIS)

    Zaitsev, A V; Kovalev, O B; Orishich, Anatolii M; Fomin, V M

    2005-01-01

    The effect of polarisation of a Gaussian beam on the radiation absorption during laser cutting of metals is investigated. A generalised formula is proposed for calculating the absorption coefficient, which describes the polarisation of three types (linear, elliptical, and circular), taking into account the fact that the beam may interact with a metal surface of an arbitrary shape. A comparison with the existing analogues (in the cases of linear and circular radiation polarisation) confirmed the advantage of employing the formula for the spatial description of the shape of the surface produced, which is highly important for processing (cutting, welding, drilling) of thick materials. The effect of laser radiation characteristics on the surface shape and cut depth in cutting stainless steel sheets is investigated numerically. It is shown for the first time that the cutting of materials by the TEM 00 beam is most efficient when the beam has elliptical polarisation directed along the direction of beam displacement and characterised by a specific axial ratio. (laser applications and other topics in quantum electronics)

  9. Correlations between polarisation states of W particles in the reaction e- e+ ---> W- W+ at LEP2 energies 189-209 GeV

    Czech Academy of Sciences Publication Activity Database

    Abdallah, J.; Abreu, P.; Adam, W.; Chudoba, Jiří; Mašík, Jiří; Rameš, Jiří; Řídký, Jan; Todorovová, Šárka; Trávníček, Petr; Vrba, Václav

    2009-01-01

    Roč. 63, č. 4 (2009), s. 611-623 ISSN 1434-6044 R&D Projects: GA MŠk LC527 Institutional research plan: CEZ:AV0Z10100502 Keywords : Delphi * polarisation * W boson Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 2.746, year: 2009 http://arxiv.org/pdf/0908.1023

  10. Spontaneous oscillations in microfluidic networks

    Science.gov (United States)

    Case, Daniel; Angilella, Jean-Regis; Motter, Adilson

    2017-11-01

    Precisely controlling flows within microfluidic systems is often difficult which typically results in systems being heavily reliant on numerous external pumps and computers. Here, I present a simple microfluidic network that exhibits flow rate switching, bistablity, and spontaneous oscillations controlled by a single pressure. That is, by solely changing the driving pressure, it is possible to switch between an oscillating and steady flow state. Such functionality does not rely on external hardware and may even serve as an on-chip memory or timing mechanism. I use an analytic model and rigorous fluid dynamics simulations to show these results.

  11. Spontaneous coronary dissection: case report

    OpenAIRE

    Couto, Gustavo J. Ventura; Deslandes, Alexandre de O.; Santos, Paulo César de Souza; Cruz, Alexandre de Araújo; Saraiva, Roberto Santos

    2007-01-01

    O objetivo do trabalho é demonstrar o caso de um homem de 62 anos, com quadro de dissecção coronariana espontânea, localizada em 1/3 inicial de coronária circunflexa esquerda, tratado cirurgicamente com revascularização miocárdica. A operação realizada com sucesso demonstra, nesse caso, ser o único meio possível de cura.The purpose of the paper is to demonstrate the case of a 62-year-old man, with spontaneous coronary dissection of the left circumflex artery, treated surgically by myocardial ...

  12. [Spontaneous neoplasms in guinea pigs].

    Science.gov (United States)

    Khar'kovskaia, N A; Khrustalev, S A; Vasil'eva, N N

    1977-01-01

    The authors present an analysis of the data of foreign literature and the results of their personal studies of spontaneous neoplasms in 40 guinea pigs of national breeding observed during observed during a 5-year period. In 4 of them malignant tumors were diagnosed-lympholeucosis (2 cases), dermoid ovarian cysts and also cancer and adenoma of the adrenal cortex (in one animal). The neoplasms described developed in guinea pigs, aged over 4 years, and they are referred to as mostly common tumors in this species of animals.

  13. LHCb: Measurement of polarisation amplitudes and triple product asymmetries in the $B_s \\to \\phi \\phi$ decay at LHCb

    CERN Multimedia

    Benson, Sean

    2012-01-01

    An untagged, time-integrated analysis of the $B_s \\to \\phi \\phi$ decay has been performed with 1 fb$^{-1}$ of pp collision data at centre-of-mass energy $\\sqrt{s} = 7$ TeV taken using the LHCb detector. Optimised selections have yielded 801 $B_s \\to \\phi \\phi$ events at high signal to background ratio. This has allowed for measurements of polarisation amplitudes ($|A_0|^2$, $|A_\\perp|^2$, $|A_\\parallel|^2$) and strong phase difference (cos$\\delta_\\parallel$) to be performed. T-violating triple product asymmetries have yielded results $A_U=-0.055 \\pm 0.036\\mathrm{(stat.)} \\pm 0.018\\mathrm{(syst.)}$ and $A_V = 0.010 \\pm 0.036\\mathrm{(stat.)} \\pm 0.018\\mathrm{(syst.)}$.

  14. Improving the efficiency of optical coherence tomography by using the non-ideal behaviour of a polarising beam splitter

    KAUST Repository

    Lippok, Norman

    2011-03-30

    We present a new way of improving the efficiency of optical coherence tomography by using the polarisation crosstalk of a polarizing beam splitter to direct most of the available source optical power to the sample. The use of a quarter wave plate in both the reference and the sample arms allows most of the sample power to be directed to the detector while adjusting the reference arm to ensure noise optimised operation. As a result, the sensitivity of such a system can be improved by 6 dB, or alternatively the acquisition time can be improved by a factor of 4 for shot noise limited performance,compared to a traditional OCT configuration using a 50/50 beam splitter. © 2011 Optical Society of America.

  15. 3D FDTD modelling of GPR: the effects of antenna polarisation on gpr signals from nonmetal pipes

    International Nuclear Information System (INIS)

    Amiruddin Shaari

    2003-01-01

    A 3D finite-difference time domain (FDTD) modelling of ground penetrating radar (GPR) has been carried out in order to determine the effectiveness of the method when it is used in a ground survey for metal and nonmetal pipes. In particular, the effects of the relative orientation between the antenna polarisation and pipe length and the dielectric contrast between ground soil and pipes on the GPR signal strength are investigated. The results show that the parallel antenna-target is the preferred orientation for metal pipes while the normal or orthogonal arrangement is the preferred one for the nonmetal pipes. The dielectric contrast between medium and target also seems to affect the strength the GPR signals from the nines. (Author)

  16. Measurement of the Longitudinal Spin Transfer to Lambda and Anti-Lambda Hyperons in Polarised Muon DIS

    CERN Document Server

    Alekseev, M.; Alexandrov, Yu.; Alexeev, G.D.; Amoroso, A.; Austregesilo, A.; Badelek, B.; Balestra, F.; Ball, J.; Barth, J.; Baum, G.; Bedfer, Y.; Bernhard, J.; Bertini, R.; Bettinelli, M.; Birsa, R.; Bisplinghoff, J.; Bordalo, P.; Bradamante, F.; Bravar, A.; Bressan, A.; Brona, G.; Burtin, E.; Bussa, M.P.; Chapiro, A.; Chiosso, M.; Chung, S.U.; Cicuttin, A.; Colantoni, M.; Crespo, M.L.; Dalla Torre, S.; Dafni, T.; Das, S.; Dasgupta, S.S.; Denisov, O.Yu.; Dhara, L.; Diaz, V.; Dinkelbach, A.M.; Donskov, S.V.; Doshita, N.; Duic, V.; Dunnweber, W.; Efremov, A.; Eversheim, P.D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; Finger, M.Jr.; Fischer, H.; Franco, C.; Friedrich, J.M.; Garfagnini, R.; Gautheron, F.; Gavrichtchouk, O.P.; Gazda, R.; Gerassimov, S.; Geyer, R.; Giorgi, M.; Gobbo, B.; Goertz, S.; Grabmuller, S.; Grajek, O.A.; Grasso, A.; Grube, B.; Gushterski, R.; Guskov, A.; Haas, F.; von Harrach, D.; Hasegawa, T.; Heckmann, J.; Heinsius, F.H.; Hermann, M.; Hermann, R.; Herrmann, F.; Hess, C.; Hinterberger, F.; Horikawa, N.; Hoppner, Ch.; d'Hose, N.; Ilgner, C.; Ishimoto, S.; Ivanov, O.; Ivanshin, Yu.; Iven, B.; Iwata, T.; Jahn, R.; Jasinski, P.; Jegou, G.; Joosten, R.; Kabuss, E.; Kang, D.; Ketzer, B.; Khaustov, G.V.; Khokhlov, Yu.A.; Kisselev, Yu.; Klein, F.; Klimaszewski, K.; Koblitz, S.; Koivuniemi, J.H.; Kolosov, V.N.; Komissarov, E.V.; Kondo, K.; Konigsmann, K.; Konopka, R.; Konorov, I.; Konstantinov, V.F.; Korzenev, A.; Kotzinian, A.M.; Kouznetsov, O.; Kowalik, K.; Kramer, M.; Kral, A.; Kroumchtein, Z.V.; Kuhn, R.; Kunne, F.; Kurek, K.; Le Goff, J.M.; Lednev, A.A.; Lehmann, A.; Levorato, S.; Lichtenstadt, J.; Liska, T.; Maggiora, A.; Maggiora, M.; Magnon, A.; Mallot, G.K.; Mann, A.; Marchand, C.; Marroncle, J.; Martin, A.; Marzec, J.; Massmann, F.; Matsuda, T.; Maximov, A.N.; Meyer, W.; Michigami, T.; Mikhailov, Yu.V.; Moinester, M.A.; Mutter, A.; Nagaytsev, A.; Nagel, T.; Nassalski, J.; Negrini, S.; Nerling, F.; Neubert, S.; Neyret, D.; Nikolaenko, V.I.; Olshevsky, A.G.; Ostrick, M.; Padee, A.; Panknin, R.; Panzieri, D.; Parsamyan, B.; Paul, S.; Pawlukiewicz-Kaminska, B.; Perevalova, E.; Pesaro, G.; Peshekhonov, D.V.; Piragino, G.; Platchkov, S.; Pochodzalla, J.; Polak, J.; Polyakov, V.A.; Pontecorvo, G.; Pretz, J.; Quintans, C.; Rajotte, J.F.; Ramos, S.; Rapatsky, V.; Reicherz, G.; Reggiani, D.; Richter, A.; Robinet, F.; Rocco, E.; Rondio, E.; Ryabchikov, D.I.; Samoylenko, V.D.; Sandacz, A.; Santos, H.; Sapozhnikov, M.G.; Sarkar, S.; Sbrizzai, G.; Schiavon, P.; Schill, C.; Schmitt, L.; Schroder, W.; Shevchenko, O.Yu.; Siebert, H.W.; Silva, L.; Sinha, L.; Sissakian, A.N.; Slunecka, M.; Smirnov, G.I.; Sosio, S.; Sozzi, F.; Srnka, A.; Stolarski, M.; Sulc, M.; Sulej, R.; Takekawa, S.; Tessaro, S.; Tessarotto, F.; Teufel, A.; Tkatchev, L.G.; Venugopal, G.; Virius, M.; Vlassov, N.V.; Vossen, A.; Weitzel, Q.; Windmolders, R.; Wislicki, W.; Wollny, H.; Zaremba, K.; Zemlyanichkina, E.; Ziembicki, M.; Zhao, J.; Zhuravlev, N.; Zvyagin, A.

    2009-01-01

    The longitudinal polarisation transfer from muons to lambda and anti-lambda hyperons, D_LL, has been studied in deep inelastic scattering off an unpolarised isoscalar target at the COMPASS experiment at CERN. The spin transfers to lambda and anti-lambda produced in the current fragmentation region exhibit different behaviours as a function of x and xF . The measured x and xF dependences of D^lambda_LL are compatible with zero, while D^anti-lambda_LL tends to increase with xF, reaching values of 0.4 - 0.5. The resulting average values are D^lambda_LL = -0.012 +- 0.047 +- 0.024 and D^anti-lambda_LL = 0.249 +- 0.056 +- 0.049. These results are discussed in the frame of recent model calculations.

  17. First measurement of the polarisation asymmetry of a gamma-ray beam between 1.7 to 74 MeV with the HARPO TPC

    Science.gov (United States)

    Gros, P.; Amano, S.; Attié, D.; Bernard, D.; Bruel, P.; Calvet, D.; Colas, P.; Daté, S.; Delbart, A.; Frotin, M.; Geerebaert, Y.; Giebels, B.; Götz, D.; Hashimoto, S.; Horan, D.; Kotaka, T.; Louzir, Marc; Minamiyama, Y.; Miyamoto, S.; Ohkuma, H.; Poilleux, Patrick; Semeniouk, I.; Sizun, P.; Takemoto, A.; Yamaguchi, M.; Wang, S.

    2016-07-01

    Current γ-ray telescopes suffer from a gap in sensitivity in the energy range between 100 keV and 100 MeV, and no polarisation measurement has ever been done on cosmic sources above 1 MeV. Past and present e+e- pair telescopes are limited at lower energies by the multiple scattering of electrons in passive tungsten converter plates. This results in low angular resolution, and, consequently, a drop in sensitivity to point sources below 1 GeV. The polarisation information, which is carried by the azimuthal angle of the conversion plane, is lost for the same reasons. HARPO is an R&D program to characterise the operation of a gaseous detector (a Time Projection Chamber or TPC) as a high angular-resolution and sensitivity telescope and polarimeter for γ-rays from cosmic sources. It represents a first step towards a future space instrument in the MeV-GeV range. We built and characterised a 30cm cubic demonstrator [SPIE 91441M], and put it in a polarised γ-ray beam at the NewSUBARU accelerator in Japan. Data were taken at photon energies from 1.74MeV to 74MeV and with different polarisation configurations. We describe the experimental setup in beam. We then describe the software we developed to reconstruct the photon conversion events, with special focus on low energies. We also describe the thorough simulation of the detector used to compare results. Finally we will present the performance of the detector as extracted from this analysis and preliminary measurements of the polarisation asymmetry. This beam-test qualification of a gas TPC prototype in a γ-ray beam could open the way to high-performance -ray astronomy and polarimetry in the MeV-GeV energy range in the near future.

  18. A first measurement of the charged current DIS cross sections with longitudinally polarised electrons in the H1 experiment at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Antunovic, B.

    2007-07-01

    The analysis presented in this thesis is based on data from electron-proton collisions with longitudinally polarised electron beams at a centre-of-mass energy of {radical}(s)=319 GeV. The data were taken with the H1 detector at the HERA collider in the year 2005 corresponding to two polarisation states: a left-handed electron polarisation of -27% and a right-handed electron polarisation of +37%, corresponding to integrated luminosities of 68.6 pb{sup -1} and 29.6 pb{sup -1}, respectively. The inclusive total deep inelastic charged current cross section and the differential cross sections are measured for both helicities in the kinematic domain Q{sup 2}>400 GeV{sup 2} and y<0.9. The entire analysis chain necessary for the determination of the cross sections is described with emphasis on the understanding of the performance of the Liquid Argon trigger system. The experimental results obtained are consistent with the predictions of the Standard Model. In particular, the measurement of the total polarised charged current cross section confirms the Standard Model expectation that there are no weak charged current interactions mediated by a hypothetical right-handed W boson. In addition, a measurement of the charged current structure function F{sup cc}{sub 2} has been performed at the H1 experiment for the first time. The measurements are well described by the theoretical expectations based on parton distributions derived from inclusive neutral current measurements in H1, and are in agreement with published data from the ZEUS (e{sup {+-}}p) and CCFR (anti {nu}{sub {mu}}Fe) experiments. (orig.)

  19. Determination of the gluon polarisation in the nucleon in the production of hadrons with high transverse momentum at Compass

    International Nuclear Information System (INIS)

    Procureur, S.

    2006-07-01

    The main goal of the COMPASS experiment at CERN is the determination of the gluon polarisation in the nucleon, V. For this, the helicity asymmetry of the photon gluon fusion process is measured, in the scattering of polarized muons on a polarised deuteron target. This process can be tagged by the production of hadrons with high transverse momentum (pT), that allows to get a large statistics. On the other hand, a physical background remains and complicates the extraction of V. This PhD thesis presents different studies performed to optimize the determination of c in this channel. In particular, a study of the alignment of the 200 detection planes is presented, leading to an improvement of the spectrometer resolution. Performances of the 12 Micromegas detectors have also been determined during 2004 run. Then, the asymmetries obtained in the analysis of 2002 to 2004 data are calculated, for various high PT selections: production of 1 or 2 hadrons, at low or high Q2. An optimization of the selection, based on a neural network, has also been developed, and a detailed study of the experimental false asymmetry has been performed. V extraction is then described, based on Monte Carlo simulations (using PYTHIA or LEPTO). For the first time, the asymmetry of the so-called resolved photon processes is estimated. An improvement on the reconstruction of nucleon momentum fraction carried by the gluon is also proposed, by reconstructing pseudo-jets. Finally, small values obtained for GG are discussed, in terms of constraints on the gluon contribution to the nucleon spin. (author)

  20. Radiological evaluation of spontaneous pneumoperitoneum

    International Nuclear Information System (INIS)

    Kim, H. S.; Kim, J. D.; Rhee, H. S.

    1982-01-01

    112 cases of spontaneous penumoperitoneum, the causes of which were confirmed by clinical and surgical procedure at Presbyterian Medical Center from January, 1977 to July, 1981 were reviewed radiologically. The results were as follows: 1. Perforation of duodenal ulcer (46/112: 41.1%), stomach ulcer (22/112: 19.6%), and stomach cancer (11/112: 9.8%) were the three most common causes of spontaneous penumoperitoneum. These were 70.5% of all causes. 2. The most common site of free gas was both subdiaphragmatic areas (46: 41.1%). Others were Rt. subdiaphragmatic only (31: 27.7%), both subdiaphragmatic with subhepatic (16: 14.3%), Rt. subdiaphragmatic with subhepatic (7: 6.2%), Rt. subdiaphragmatic only (5: 4.4%), diffuse in abdomen (4: 3.6%), and subhepatic only (3: 2.7%). So 92.0% (103/112) were located in RUQ. 3. The radiological shape of free gas was classified: crescent (52: 46.4%) of small amount; half-moon (21: 18.8%) of moderate amount; large or diffuse (39: 34.8%) of large amount.4. The age between 31 and 60 occupied 69.1% (77/112), and male was predominant (5.2 times). 5. The patient's position showing free air most frequently was erect

  1. On transient electric fields observed in chemical release experiments by rockets

    International Nuclear Information System (INIS)

    Marklund, G.; Brenning, N.; Holmgren, G.; Haerendel, G.

    1986-06-01

    As a follow-up to the successful chemical release experiment Trigger in 1977, the TOR (Trigger Optimized Repetition) rocket was launched from Esrange on Oct. 24, 1984. Like in the Trigger experiment a large amplitude electric field pulse of 200 mV/m was detected shortly after the explosion. The central part of the pulse was found to be clearly correlated with an intense layer of swept up ambient particles behind a propagating shock-front. The field was directed towards the centre of the expanding ionized cloud, which is indicative of a polarisation electric field source. Expressions for this radial polarisation field and the much weaker azimuthal induced electric field are derived from a simple cylindrical model for the field and the expanding neutral cloud. Time profiles of the radial electric field are shown to be in good agreement with observations. (authors)

  2. Compton polarimetry of 6-35 keV X-rays. Influence of Breit interaction on the linear polarisation of KLL dielectronic recombination transitions in highly charged ions

    Energy Technology Data Exchange (ETDEWEB)

    Joerg, Holger Eric

    2016-12-21

    The polarisation of X-rays emitted during K shell dielectronic recombination (DR) into highly charged ions was studied using electron beam ion traps. In the first experiment, the degree of linear polarisation of X-rays due to K shell DR transitions of highly charged krypton ions was measured with a newly developed Compton polarimeter based on SiPIN diodes. Such polarisation measurements allow a study of the population mechanism of magnetic sublevels in collisions between electrons and ions. In a second experiment, the influence of Breit interaction between electrons on the polarisation of X-rays emitted during K shell DR into highly charged xenon ions was studied. Here, polarisation measurements provide an access to the finer details of the electron-electron interaction in electron-ion collisions. Furthermore, a second Compton polarimeter based on silicon drift detectors has been developed for polarisation measurements at synchrotrons. It has been developed for X-ray polarimetry with a high energy resolution for energies between 6 keV and 35 keV. It was tested in the course of polarisation measurements at an electron beam ion trap and at a synchrotron radiation source.

  3. A Case of Multiple Spontaneous Keloid Scars

    Directory of Open Access Journals (Sweden)

    Abdulhadi Jfri

    2015-07-01

    Full Text Available Keloid scars result from an abnormal healing response to cutaneous injury or inflammation that extends beyond the borders of the original wound. Spontaneous keloid scars forming in the absence of any previous trauma or surgical procedure are rare. Certain syndromes have been associated with this phenomenon, and few reports have discussed the evidence of single spontaneous keloid scar, which raises the question whether they are really spontaneous. Here, we present a 27-year-old mentally retarded single female with orbital hypertelorism, broad nasal bridge, repaired cleft lip and high-arched palate who presented with progressive multiple spontaneous keloid scars in different parts of her body which were confirmed histologically by the presence of typical keloidal collagen. This report supports the fact that keloid scars can appear spontaneously and are possibly linked to a genetic factor. Furthermore, it describes a new presentation of spontaneous keloid scars in the form of multiple large lesions in different sites of the body.

  4. Noncritical quadrature squeezing through spontaneous polarization symmetry breaking

    OpenAIRE

    Garcia-Ferrer, Ferran V.; Navarrete-Benlloch, Carlos; de Valcárcel, Germán J.; Roldán, Eugenio

    2010-01-01

    We discuss the possibility of generating noncritical quadrature squeezing by spontaneous polarization symmetry breaking. We consider first type-II frequency-degenerate optical parametric oscillators, but discard them for a number of reasons. Then we propose a four-wave mixing cavity in which the polarization of the output mode is always linear but has an arbitrary orientation. We show that in such a cavity complete noise suppression in a quadrature of the output field occurs, irrespective of ...

  5. Noncritical quadrature squeezing through spontaneous polarization symmetry breaking.

    Science.gov (United States)

    Garcia-Ferrer, Ferran V; Navarrete-Benlloch, Carlos; de Valcárcel, Germán J; Roldán, Eugenio

    2010-07-01

    We discuss the possibility of generating noncritical quadrature squeezing by spontaneous polarization symmetry breaking. We first consider Type II frequency-degenerate optical parametric oscillators but discard them for a number of reasons. Then we propose a four-wave-mixing cavity, in which the polarization of the output mode is always linear but has an arbitrary orientation. We show that in such a cavity, complete noise suppression in a quadrature of the output field occurs, irrespective of the parameter values.

  6. Deep inelastic scattering in spontaneously broken gauge models

    International Nuclear Information System (INIS)

    Goloskokov, S.V.; Mikhov, S.G.; Morozov, P.T.; Stamenov, D.B.

    1975-01-01

    Deep inelastic lepton hadron scattering in the simplest spontaneously broken symmetry (the Kibble model) is analyzed. A hypothesis that the invariant coupling constant of the quartic selfinteraction for large spacelike momenta tends to a finite asymptotic value without spoiling the asymptotic freedom for the invariant coupling constant of the Yang-Mills field is used. It is shown that Biorken scaling for the moments of the structure functions of the deep inelastic lepton hadron scattering is violated by powers of logarithms

  7. Spontaneous Intracranial Hypotension without Orthostatic Headache

    Directory of Open Access Journals (Sweden)

    Tülay Kansu

    2009-03-01

    Full Text Available We report 2 cases of spontaneous intracranial hypotension that presented with unilateral abducens nerve palsy, without orthostatic headache. While sixth nerve palsies improved without any intervention, subdural hematoma was detected with magnetic resonance imaging. We conclude that headache may be absent in spontaneous intracranial hypotension and spontaneous improvement of sixth nerve palsy can occur, even after the development of a subdural hematoma

  8. Spontaneous pneumothorax in silicotuberculosis of lung

    International Nuclear Information System (INIS)

    Kolenic, J.; Jurgova, T.; Zimacek, J.; Vajo, J.; Krchnavy, M.

    1995-01-01

    The authors describe the case of 62 years old man with the appearance of spontaneous pneumothorax, in whom the basic pulmonary disease was silicotuberculosis of the lung. At clinic of occupational diseases in Kosice have been evidence 965 cases of silicosis and silicotuberculosis. From 1971 they have now the first case of spontaneous pneumothorax. The authors make discussion about possible mechanical and biochemical factors, which cause relatively low incidence of spontaneous pneumothorax in silicosis of the lung. (authors)

  9. Spontaneous emission of the non-Wiener type

    International Nuclear Information System (INIS)

    Basharov, A. M.

    2011-01-01

    The spontaneous emission of a quantum particle and superradiation of an ensemble of identical quantum particles in a vacuum electromagnetic field with zero photon density are examined under the conditions of significant Stark particle and field interaction. New fundamental effects are established: suppression of spontaneous emission by the Stark interaction, an additional “decay” shift in energy of the decaying level as a consequence of Stark interaction unrelated to the Lamb and Stark level shifts, excitation conservation phenomena in a sufficiently dense ensemble of identical particles and suppression of superradiaton in the decay of an ensemble of excited quantum particles of a certain density. The main equations describing the emission processes under conditions of significant Stark interaction are obtained in the effective Hamiltonian representation of quantum stochastic differential equations. It is proved that the Stark interaction between a single quantum particle and a broadband electromagnetic field is represented as a quantum Poisson process and the stochastic differential equations are of the non-Wiener (generalized Langevin) type. From the examined case of spontaneous emission of a quantum particle, the main rules are formulated for studying open systems in the effective Hamiltonian representation.

  10. Osteonecrosis or spontaneous fractures following renal transplantation

    International Nuclear Information System (INIS)

    Andresen, J.; Nielsen, H.E.; Aarhus Univ.

    1981-01-01

    31 renal transplant recipients with posttransplant development of osteonecrosis or spontaneous fractures were evaluated with regard to age, duration of dialysis before transplantation. Determination of metacarpal bone mass at the time of transplantation and registration of bone resorption and soft tissue calcification at the time of transplantation and at the time of onset of osteonecrosis and spontaneous fractures were made. Apart from the increased mean age in patients with spontaneous fractures no difference was seen between the groups. Osteonecrosis and spontaneous fractures occurred in areas of trabecular bone. It seems most likely that after renal transplantation the patients show bone complications of different localization. (orig.) [de

  11. Reformulation od spontaneous symmetry breaking and the Weinberg-Salam model

    International Nuclear Information System (INIS)

    Rawat, A.S.; Rawat, S.; Negi, O.P.S.

    1999-01-01

    Spontaneous symmetry breaking and the Weinberg-Salam model have been reformulated in terms of quaternion-valued field variables. The quaternion-valued scalar Lagrangian reduces to four different field equations associated with the scalar quartet of a quaternion field φ φ 0 +e 1φ1 +e 2φ2 +e 3φ3 . It has been shown that the quaternion gauge group SO(4) is spontaneously broken to two gauge groups of SU(2) non Abelian gauge fields. The Weinberg-Salam model of electroweak interaction has been extensively studied to enlarge the gauge group structure SU(2) L xSU(2) R xU(1)

  12. Study of a polarized proton source for a cyclotron using a high frequency transition (1961); Etude d'une source de protons polarises utilisant une transition haute frequence pour un cyclotron (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Thirion, J; Beurtey, R; Papineau, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    The authors have developed an experimental unit yielding a jet of hydrogen or deuterium atoms in which the protons and deutons are polarized. By use of the 'adiabatic passage' method a proton polarisation approaching 100 per cent is assured. (authors) [French] Les auteurs ont mis au point un ensemble experimental permettant d'obtenir un jet d'atomes d'hydrogene ou de deuterium, dans lequel les protons et les deutons sont polarises. Grace a la methode du 'passage adiabatique' une polarisation de protons voisine de 100 pour cent est obtenue. (auteurs)

  13. Spontaneous non aneurysmal subarachnoid hemorrhage

    International Nuclear Information System (INIS)

    Bian Jieyong; Wang Zhong; Zhou Dai

    2000-01-01

    Objective: To study the etiology and the treatment of spontaneous non-aneurysmal subarachnoid hemorrhage. Methods: Twenty five cases of cerebral vessel angiography negative patients were analysed retrospectively, the majority of them had been undergone CT, DSA, MRI examination in order to define the etiological factor. Results: Among them, there was 1 case of spinal arteria-vena malformation, 1 case of hemorrhagic blood and 2 cases according to the revealing of MRI could be explained as bled vascular-occult malformation or cavernous angioma. Conclusion: The management and prognosis of patients in whom non-aneurysm is founded on the initial angiogram depends on the pattern of hemorrhage of the initial CT scanning, repeated angiography should be avoided for the case of premise encephalic non-aneurysmal SAH and MRI examination may be indicated to defining of etiological factors

  14. Crows spontaneously exhibit analogical reasoning.

    Science.gov (United States)

    Smirnova, Anna; Zorina, Zoya; Obozova, Tanya; Wasserman, Edward

    2015-01-19

    Analogical reasoning is vital to advanced cognition and behavioral adaptation. Many theorists deem analogical thinking to be uniquely human and to be foundational to categorization, creative problem solving, and scientific discovery. Comparative psychologists have long been interested in the species generality of analogical reasoning, but they initially found it difficult to obtain empirical support for such thinking in nonhuman animals (for pioneering efforts, see [2, 3]). Researchers have since mustered considerable evidence and argument that relational matching-to-sample (RMTS) effectively captures the essence of analogy, in which the relevant logical arguments are presented visually. In RMTS, choice of test pair BB would be correct if the sample pair were AA, whereas choice of test pair EF would be correct if the sample pair were CD. Critically, no items in the correct test pair physically match items in the sample pair, thus demanding that only relational sameness or differentness is available to support accurate choice responding. Initial evidence suggested that only humans and apes can successfully learn RMTS with pairs of sample and test items; however, monkeys have subsequently done so. Here, we report that crows too exhibit relational matching behavior. Even more importantly, crows spontaneously display relational responding without ever having been trained on RMTS; they had only been trained on identity matching-to-sample (IMTS). Such robust and uninstructed relational matching behavior represents the most convincing evidence yet of analogical reasoning in a nonprimate species, as apes alone have spontaneously exhibited RMTS behavior after only IMTS training. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Recurrent spontaneous attacks of dizziness.

    Science.gov (United States)

    Lempert, Thomas

    2012-10-01

    This article describes the common causes of recurrent vertigo and dizziness that can be diagnosed largely on the basis of history. Ninety percent of spontaneous recurrent vertigo and dizziness can be explained by six disorders: (1) Ménière disease is characterized by vertigo attacks, lasting 20 minutes to several hours, with concomitant hearing loss, tinnitus, and aural fullness. Aural symptoms become permanent during the course of the disease. (2) Attacks of vestibular migraine may last anywhere from minutes to days. Most patients have a previous history of migraine headaches, and many experience migraine symptoms during the attack. (3) Vertebrobasilar TIAs affect older adults with vascular risk factors. Most attacks last less than 1 hour and are accompanied by other symptoms from the posterior circulation territory. (4) Vestibular paroxysmia is caused by vascular compression of the eighth cranial nerve. It manifests itself with brief attacks of vertigo that recur many times per day, sometimes with concomitant cochlear symptoms. (5) Orthostatic hypotension causes brief episodes of dizziness lasting seconds to a few minutes after standing up and is relieved by sitting or lying down. In older adults, it may be accompanied by supine hypertension. (6) Panic attacks usually last minutes, occur in specific situations, and are accompanied by choking, palpitations, tremor, heat, and anxiety. Less common causes of spontaneous recurrent vertigo and dizziness include perilymph fistula, superior canal dehiscence, autoimmune inner ear disease, otosclerosis, cardiac arrhythmia, and medication side effects. Neurologists need to venture into otolaryngology, internal medicine, and psychiatry to master the differential diagnosis of recurrent dizziness.

  16. Spontaneously broken abelian gauge invariant supersymmetric model

    International Nuclear Information System (INIS)

    Mainland, G.B.; Tanaka, K.

    A model is presented that is invariant under an Abelian gauge transformation and a modified supersymmetry transformation. This model is broken spontaneously, and the interplay between symmetry breaking, Goldstone particles, and mass breaking is studied. In the present model, spontaneously breaking the Abelian symmetry of the vacuum restores the invariance of the vacuum under a modified supersymmetry transformation. (U.S.)

  17. Spontaneous onset of Complex Regional Pain Syndrome

    NARCIS (Netherlands)

    de Rooij, A.M.; Perez, R.S.G.M.; Huygen, F.J.; van Eijs, F.; van Kleef, M.; Bauer, M.C.R.; van Hilten, J.J.; Marinus, J.

    2010-01-01

    Complex Regional Pain Syndrome (CRPS) usually develops after a noxious event, but spontaneous onsets have been described in 3-11% of the cases. The existence of spontaneous-onset CRPS is highly debated and the aim of the present study was therefore to compare the phenotypic characteristics of CRPS

  18. Spontaneous CP violation on the lattice

    CERN Document Server

    Laine, Mikko

    2000-01-01

    At finite temperatures around the electroweak phase transition, the thermodynamics of the MSSM can be described by a three-dimensional two Higgs doublet effective theory. This effective theory has a phase where CP is spontaneously violated. We study spontaneous CP violation with non-perturbative lattice simulations, and analyse whether one could end up in this phase for any physical MSSM parameter values.

  19. Spontaneous rupture of choledochal cyst: case report

    International Nuclear Information System (INIS)

    Shin, Ho Seob; Nam, Kyung Jin; Lee, Jin Hwa; Kim, Chan Sung; Choi, Jong Cheol; Oh, Jong Young

    2002-01-01

    Spontaneous rupture of a choledochal cyst leading to biliary peritonitis is a rare complication which can be fatal if not promptly diagnosed. The authors report the ultrasound and CT findings of two cases of spontaneous choledochal cystic rupture and the biliary peritonitis which ensued

  20. Spontaneous pneumomediastinum after bench press training.

    Science.gov (United States)

    Nishino, Tomoya

    2017-04-01

    Spontaneous pneumomediastinum is often associated with asthma and mainly affects adolescent males with a tall, thin body habitus. A 17-year-old man complained of chest and pharyngeal pain after bench press training and spontaneous pneumomediastinum was diagnosed. It should be considered in the differential diagnosis of chest pain of uncertain cause.

  1. Spontaneous Achilles tendon rupture in alkaptonuria | Mohammed ...

    African Journals Online (AJOL)

    Spontaneous Achilles tendon ruptures are uncommon. We present a 46-year-old man with spontaneous Achilles tendon rupture due to ochronosis. To our knowledge, this has not been previously reported in Sudan literature. The tendon of the reported patient healed well after debridement and primary repairs.

  2. Spontaneous rupture of choledochal cyst: case report

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Ho Seob; Nam, Kyung Jin; Lee, Jin Hwa; Kim, Chan Sung; Choi, Jong Cheol; Oh, Jong Young [Dong-a University College of Medicine, Pusan (Korea, Republic of)

    2002-11-01

    Spontaneous rupture of a choledochal cyst leading to biliary peritonitis is a rare complication which can be fatal if not promptly diagnosed. The authors report the ultrasound and CT findings of two cases of spontaneous choledochal cystic rupture and the biliary peritonitis which ensued.

  3. Children's Spontaneous Vocalisations during Play: Aesthetic Dimensions

    Science.gov (United States)

    Countryman, June; Gabriel, Martha; Thompson, Katherine

    2016-01-01

    This paper explores the phenomenon of spontaneous vocalisations in the self-chosen, unstructured outdoor play of children aged 3-12. Spontaneous vocalisations encompass the whole range of children's unprompted, natural, expressive vocal soundings beyond spoken language. Non-participant observations at childcare centres and on elementary school…

  4. Frequency shifts in spontaneous emission from two interacting atoms

    International Nuclear Information System (INIS)

    James, D.F.V.

    1993-01-01

    A model radiating system consisting of two atoms in close proximity is analyzed. This system demonstrates the influence of spatial coherence on the spectrum of the radiation field. Explicit expressions for the degree of coherence, the source spectrum, and the spectrum of the radiation field are derived. The results are discussed in terms of Wolf's work [Phys. Rev. Lett. 56, 1370 (1986)] on this effect, which can be considered in terms of a multiple-atom analog of the effects of radiation reaction on a single atom, i.e., spontaneous decay and the Lamb shift

  5. Kinetics of spontaneous baryogenesis in non-stationary background

    Directory of Open Access Journals (Sweden)

    Arbuzova Elena

    2016-01-01

    Full Text Available Generation of the cosmological baryon asymmetry in frameworks of spontaneous baryogenesis is studied in detail. It is shown that the relation between baryonic chemical potential and the time derivative of the (pseudoGoldstone field essentially depends upon the representation chosen for the fermionic fields with non-zero baryonic number (quarks. Kinetic equation is modified and numerically solved in equilibrium for the case of time dependent external background or finite integration time to be applicable to the case when energy conservation law is formally violated.

  6. German private mobile telecommunication research program. Effects of a) low-frequency magnetic fields, b) GSM mobile telecommunication signals, c) UMTS signals on the spontaneous leukemia rate of AKR mice

    International Nuclear Information System (INIS)

    2006-01-01

    Since the introduction of private mobile telecommunication about 10 years ago, there is a worldwide discussion about the possible adverse health effects of such highfrequency electromagnetic fields (EMF). Main concerns are regarding the possible cancerogenic or promoting effect of mobile phones and base stations. The insecurity of the public is increased by the continuous development of new techniques and introduction of new systems (e.g. wireless LAN, UMTS), for which insufficient data are available about their possible health hazards. This project's aim was therefore to investigate if chronic exposure to EMF of the UMTS-standard will influence leukaemia or the development of solid tumors in an animal model. The experiment was performed with AKR mice, which is an accepted animal model for leukaemia. With high probability, these mice develop the disease within their lifespan, so that the time course of the onset of leukaemia, bodyweight, blood picture, time of survival, and pathological examinations were the endpoints of the investigation. 160 female AKR/J mice were exposed or sham-exposed for 24 hours per day to EMF of the UMTS-standard (0.4 W/kg SAR). Additionally, 33 animals were kept as cagecontrols. For this experiment special radial waveguides were constructed and built which have a low SAR variability. All experiments were performed in a blinded fashion. The only significant difference between exposed and sham-exposed mice was a higher survival rate of exposed animals. However, the number of ill animals, the mean survival time and the severity code of the disease did not differ between the experimental groups. Animals of the cage-control group had a significant lower growth rate compared to animals kept in the radial waveguides, likely the cause of differences in the method of food supply. The results of this study don't show any negative effects of the exposure. The results do not show any negative effects of exposure for months to EMF at levels 5-fold the

  7. Early pregnancy angiogenic markers and spontaneous abortion

    DEFF Research Database (Denmark)

    Andersen, Louise B; Dechend, Ralf; Karumanchi, S Ananth

    2016-01-01

    BACKGROUND: Spontaneous abortion is the most commonly observed adverse pregnancy outcome. The angiogenic factors soluble Fms-like kinase 1 and placental growth factor are critical for normal pregnancy and may be associated to spontaneous abortion. OBJECTIVE: We investigated the association between...... maternal serum concentrations of soluble Fms-like kinase 1 and placental growth factor, and subsequent spontaneous abortion. STUDY DESIGN: In the prospective observational Odense Child Cohort, 1676 pregnant women donated serum in early pregnancy, gestational week ..., interquartile range 71-103). Concentrations of soluble Fms-like kinase 1 and placental growth factor were determined with novel automated assays. Spontaneous abortion was defined as complete or incomplete spontaneous abortion, missed abortion, or blighted ovum

  8. A hybrid nanoantenna for highly enhanced directional spontaneous emission

    Energy Technology Data Exchange (ETDEWEB)

    Chou, R. Yuanying; Lu, Guowei, E-mail: guowei.lu@pku.edu.cn; Shen, Hongming; He, Yingbo; Cheng, Yuqing [State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China); Perriat, Pascal [MATEIS, UMR 5510 CNRS, INSA-Lyon, Université de Lyon, Villeurbanne Cedex 69621 (France); Martini, Matteo; Tillement, Olivier [ILM, UMR 5306 CNRS, Université de Lyon, Villeurbanne Cedex 69622 (France); Gong, Qihuang [State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China); Collaborative Innovation Center of Quantum Matter, Beijing 100871 (China)

    2014-06-28

    Spontaneous emission modulated by a hybrid plasmonic nanoantenna has been investigated by employing finite-difference time-domain method. The hybrid nanoantenna configurations constituted by a gap hot-spot and of a plasmonic corrugated grating and a metal reflector sandwiching a SiO{sub 2} thin layer which appears promising for high spontaneous emission enhancement devices. Simulation assays show that the coupling between the gap-antenna and plasmonic corrugations reaches an ultra-high near-field enhancement factor in the excitation process. Moreover, concerning the emission process, the corrugations concentrate the far-field radiated power within a tiny angular volume, offering unprecedented collection efficiency. In the past decades, many kinds of optical antennas have been proposed and optimized to enhance single molecule detection. However, the excitation enhancement effect for single individual or dimmer plasmonic nanostructure is limited due to intrinsic nonradiative decay of the nanoparticle plasmon and quantum tunneling effect. The proposed hybrid configuration overwhelms the enhancement limit of single individual plasmonic structure. The findings provide an insight into spontaneous emission high enhancement through integrating the functions of different metallic nanostructures.

  9. A hybrid nanoantenna for highly enhanced directional spontaneous emission

    International Nuclear Information System (INIS)

    Chou, R. Yuanying; Lu, Guowei; Shen, Hongming; He, Yingbo; Cheng, Yuqing; Perriat, Pascal; Martini, Matteo; Tillement, Olivier; Gong, Qihuang

    2014-01-01

    Spontaneous emission modulated by a hybrid plasmonic nanoantenna has been investigated by employing finite-difference time-domain method. The hybrid nanoantenna configurations constituted by a gap hot-spot and of a plasmonic corrugated grating and a metal reflector sandwiching a SiO 2 thin layer which appears promising for high spontaneous emission enhancement devices. Simulation assays show that the coupling between the gap-antenna and plasmonic corrugations reaches an ultra-high near-field enhancement factor in the excitation process. Moreover, concerning the emission process, the corrugations concentrate the far-field radiated power within a tiny angular volume, offering unprecedented collection efficiency. In the past decades, many kinds of optical antennas have been proposed and optimized to enhance single molecule detection. However, the excitation enhancement effect for single individual or dimmer plasmonic nanostructure is limited due to intrinsic nonradiative decay of the nanoparticle plasmon and quantum tunneling effect. The proposed hybrid configuration overwhelms the enhancement limit of single individual plasmonic structure. The findings provide an insight into spontaneous emission high enhancement through integrating the functions of different metallic nanostructures.

  10. Modal analysis of spontaneous emission in a planar microcavity

    International Nuclear Information System (INIS)

    Rigneault, H.; Monneret, S.

    1996-01-01

    A complete set of cavity modes in planar dielectric microcavities is presented which naturally includes guided modes. We show that most of these orthonormal fields can be derived from a coherent superposition of plane waves incoming on the stack from the air and from the substrate. Spontaneous emission of a dipole located inside the microcavity is analyzed, in terms of cavity modes. Derivation of the radiation pattern in the air and in the substrate is presented. The power emitted into the guided modes is also determined. Finally, a numerical analysis of the radiative properties of an erbium atom located in a Fabry-Pacute erot multilayer dielectric microcavity is investigated. We show that a large amount of light is emitted into the guided modes of the structure, in spite of the Fabry-Pacute erot resonance, which increases the spontaneous emission rate in a normal direction. copyright 1996 The American Physical Society

  11. Towards spontaneous parametric down-conversion at low temperatures

    Directory of Open Access Journals (Sweden)

    Akatiev Dmitrii

    2017-01-01

    Full Text Available The possibility of observing spontaneous parametric down-conversion in doped nonlinear crystals at low temperatures, which would be useful for combining heralded single-photon sources and quantum memories, is studied theoretically. The ordinary refractive index of a lithium niobate crystal doped with magnesium oxide LiNbO3:MgO is measured at liquid nitrogen and helium temperatures. On the basis of the experimental data, the coefficients of the Sellmeier equation are determined for the temperatures from 5 to 300 K. In addition, a poling period of the nonlinear crystal has been calculated for observing type-0 spontaneous parametric down-conversion (ooo-synchronism at the liquid helium temperature under pumping at the wavelength of λp = 532 nm and emission of the signal field at the wavelength of λs = 794 nm, which corresponds to the resonant absorption line of Tm3+ doped ions.

  12. Dark matter, baryon asymmetry, and spontaneous B and L breaking

    International Nuclear Information System (INIS)

    Dulaney, Timothy R.; Wise, Mark B.; Perez, Pavel Fileviez

    2011-01-01

    We investigate the dark matter and the cosmological baryon asymmetry in a simple theory where baryon (B) and lepton (L) number are local gauge symmetries that are spontaneously broken. In this model, the cold dark matter candidate is the lightest new field with baryon number and its stability is an automatic consequence of the gauge symmetry. Dark matter annihilation is either through a leptophobic gauge boson whose mass must be below a TeV or through the Higgs boson. Since the mass of the leptophobic gauge boson has to be below the TeV scale, one finds that in the first scenario there is a lower bound on the elastic cross section of about 5x10 -46 cm 2 . Even though baryon number is gauged and not spontaneously broken until the weak scale, a cosmologically acceptable baryon excess is possible. There can be a tension between achieving both the measured baryon excess and the dark matter density.

  13. Electrically Controllable Spontaneous Magnetism in Nanoscale Mixed Phase Multiferroics

    Energy Technology Data Exchange (ETDEWEB)

    He, Q.; Chu, Y. H.; Heron, J. T.; Yang, S. Y.; Wang, C. H.; Kuo, C. Y.; Lin, H. J.; Yu, P.; Liang, C. W.; Zeches, R. J.; Chen, C. T.; Arenholz, E.; Scholl, A.; Ramesh, R.

    2010-08-02

    The emergence of enhanced spontaneous magnetic moments in self-assembled, epitaxial nanostructures of tetragonal (T-phase) and rhombohedral phases (R-phase) of the multiferroic BiFeO{sub 3} system is demonstrated. X-ray magnetic circular dichroism based photoemission electron microscopy (PEEM) was applied to investigate the local nature of this magnetism. We find that the spontaneous magnetization of the R-phase is significantly enhanced above the canted antiferromagnetic moment in the bulk phase, as a consequence of a piezomagnetic coupling to the adjacent T-phase and the epitaxial constraint. Reversible electric field control and manipulation of this magnetic moment at room temperature is shown using a combination of piezoresponse force microscopy and PEEM studies.

  14. Inertial Spontaneous Symmetry Breaking and Quantum Scale Invariance

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Pedro G. [Oxford U.; Hill, Christopher T. [Fermilab; Ross, Graham G. [Oxford U., Theor. Phys.

    2018-01-23

    Weyl invariant theories of scalars and gravity can generate all mass scales spontaneously, initiated by a dynamical process of "inertial spontaneous symmetry breaking" that does not involve a potential. This is dictated by the structure of the Weyl current, $K_\\mu$, and a cosmological phase during which the universe expands and the Einstein-Hilbert effective action is formed. Maintaining exact Weyl invariance in the renormalised quantum theory is straightforward when renormalisation conditions are referred back to the VEV's of fields in the action of the theory, which implies a conserved Weyl current. We do not require scale invariant regulators. We illustrate the computation of a Weyl invariant Coleman-Weinberg potential.

  15. Coherent manipulation of spontaneous emission spectra in coupled semiconductor quantum well structures.

    Science.gov (United States)

    Chen, Aixi

    2014-11-03

    In triple coupled semiconductor quantum well structures (SQWs) interacting with a coherent driving filed, a coherent coupling field and a weak probe field, spontaneous emission spectra are investigated. Our studies show emission spectra can easily be manipulated through changing the intensity of the driving and coupling field, detuning of the driving field. Some interesting physical phenomena such as spectral-line enhancement/suppression, spectral-line narrowing and spontaneous emission quenching may be obtained in our system. The theoretical studies of spontaneous emission spectra in SQWS have potential application in high-precision spectroscopy. Our studies are based on the real physical system [Appl. Phys. Lett.86(20), 201112 (2005)], and this scheme might be realizable with presently available techniques.

  16. Effective potential for spontaneously broken gauge theories and gauge hierarchies

    International Nuclear Information System (INIS)

    Hagiwara, T.; Ovrut, B.

    1979-01-01

    The Appelquist-Carazzone effective-field-theory method, where one uses effective light-field coupling constants dependent on the heavy-field sector, is explicitly shown to be valid for the discussion of the gauge-hierarchy problem in grand unified gauge models. Using the method of functionals we derive an expression for the one-loop approximation to the scalar-field effective potential for spontaneously broken theories in an arbitrary R/sub xi/ gauge. We argue that this potential generates, through its derivatives, valid zero-momentum, one-particle-irreducible vertices for any value of xi (not just the xi→infinity Landau gauge). The equation that the one-loop vacuum correction must satisfy is presented, and we solve this equation for a number of spontaneously broken theories including gauge theories with gauge groups U(1) and SO(3). We find that a one-loop vacuum shift in a massless, non-Goldstone direction occurs via the Coleman-Weinberg mechanism with an effective coupling constant dependent on the heavy-field sector

  17. Miniemulsification process - different form of spontaneous emulsification

    Energy Technology Data Exchange (ETDEWEB)

    El-Aasser, M.S.; Lack, C.D.; Vanderhoff, J.W.; Fowkes, F.M.

    1988-01-15

    The miniemulsification process involves the use of low concentrations of mixed emulsifier combinations of an ionic surfactant (e.g. sodium lauryl sulfate) and a cosurfactant (e.g. long-chain fatty alcohol - cetyl alcohol). The product is an oil-in-water miniemulsion with an average droplet diameter of 100-400 nm, and excellent shelf stability. The dominant presence of liquid crystals in the aqueous mixed emulsifier system, under conditions of the miniemulsification process, was confirmed by consideration of phase diagrams, conductivity and birefringence studies. Unexpectedly, interfacial tension studies showed relatively high values of 5-15 dyn cm/sup -1/. In spite of these high interfacial tensions, spontaneous emulsification was found at the oil-water interface, contrary to what is known in the field. Adsorption and electrophoretic mobility studies suggested that the miniemulsification process takes place by unidirectional swelling of the lamellar bilayers in the aqueous mixed emulsifier liquid crystal system as a result of absorption of oil, followed by subdivision of these entities. The stability of miniemulsions formed by this process is influenced by a steric component in the mixed emulsifier complex adsorbed at the oil-water interface.

  18. Bilateral spontaneous hemotympanum: Case report

    Directory of Open Access Journals (Sweden)

    Economou Nicolas C

    2006-10-01

    Full Text Available Abstract Background The most common causes of hemotympanum are therapeutic nasal packing, epistaxis, blood disorders and blunt trauma to the head. Hemotympanum is characterized as idiopathic, when it is detected in the presence of chronic otitis media. A rare case of spontaneous bilateral hemotympanum in a patient treated with anticoagulants is presented herein. Case presentation A 72-year-old male presented with acute deterioration of hearing. In the patient's medical history aortic valve replacement 1 year before presentation was reported. Since then he had been administered regularly coumarinic anticoagulants, with INR levels maintained between 3.4 and 4.0. Otoscopy revealed the presence of bilateral hemotympanum. The audiogram showed symmetrical moderately severe mixed hearing loss bilaterally, with the conductive component predominating. Tympanograms were flat bilaterally with absent acoustic reflexes. A computerized tomography scan showed the presence of fluid in the mastoid and middle ear bilaterally. Treatment was conservative and consisted of a 10-day course of antibiotics, anticongestants and temporary interruption of the anticoagulant therapy. After 3 weeks, normal tympanic membranes were found and hearing had returned to previous levels. Conclusion Anticoagulant intake should be included in the differential diagnosis of hemotympanum, because its detection and appropriate treatment may lead to resolution of the disorder.

  19. Spontaneous flocking in human groups.

    Science.gov (United States)

    Belz, Michael; Pyritz, Lennart W; Boos, Margarete

    2013-01-01

    Flocking behaviour, as a type of self-organised collective behaviour, is described as the spatial formation of groups without global control and explicit inter-individual recruitment signals. It can be observed in many animals, such as bird flocks, shoals or herds of ungulates. Spatial attraction between humans as the central component of flocking behaviour has been simulated in a number of seminal models but it has not been detected experimentally in human groups so far. The two other sub-processes of this self-organised collective movement - collision avoidance and alignment - are excluded or held constant respectively in this study. We created a computer-based, multi-agent game where human players, represented as black dots, moved on a virtual playground. The participants were deprived of social cues about each other and could neither communicate verbally nor nonverbally. They played two games: (1) Single Game, where other players were invisible, and (2) Joint Game, where each player could see players' positions in a local radius around himself/herself. We found that individuals approached their neighbours spontaneously if their positions were visible, leading to less spatial dispersion of the whole group compared to moving alone. We conclude that human groups show the basic component of flocking behaviour without being explicitly instructed or rewarded to do so. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Spontaneous Metacognition in Rhesus Monkeys.

    Science.gov (United States)

    Rosati, Alexandra G; Santos, Laurie R

    2016-09-01

    Metacognition is the ability to think about thinking. Although monitoring and controlling one's knowledge is a key feature of human cognition, its evolutionary origins are debated. In the current study, we examined whether rhesus monkeys (Macaca mulatta; N = 120) could make metacognitive inferences in a one-shot decision. Each monkey experienced one of four conditions, observing a human appearing to hide a food reward in an apparatus consisting of either one or two tubes. The monkeys tended to search the correct location when they observed this baiting event, but engaged in information seeking-by peering into a center location where they could check both potential hiding spots-if their view had been occluded and information seeking was possible. The monkeys only occasionally approached the center when information seeking was not possible. These results show that monkeys spontaneously use information about their own knowledge states to solve naturalistic foraging problems, and thus provide the first evidence that nonhumans exhibit information-seeking responses in situations with which they have no prior experience. © The Author(s) 2016.