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Sample records for longitudinal spin structure

  1. Nucleon Spin Structure: Longitudinal and Transverse

    SciTech Connect

    Jian-Ping Chen

    2011-02-01

    Inclusive Deep-Inelastic Scattering (DIS) experiments have provided us with the most extensive information on the unpolarized and longitudinal polarized parton (quark and gluon) distributions in the nucleon. It has becoming clear that transverse spin and transverse momentum dependent distributions (TMDs) study are crucial for a more complete understanding of the nucleon structure and the dynamics of the strong interaction. The transverse spin structure and the TMDs are the subject of increasingly intense theoretical and experimental study recently. With a high luminosity electron beam facility, JLab has played a major role in the worldwide effort to study both the longitudinal and transverse spin structure. Highlights of recent results will be presented. With 12-GeV energy upgrade, JLab will provide the most precise measurements in the valence quark region to close a chapter in longitudinal spin study. JLab will also perform a multi-dimensional mapping of the transverse spin structure and TMDs in the valence quark region through Semi-Inclusive DIS (SIDIS) experiments, providing a 3-d partonic picture of the nucleon in momentum space and extracting the u and d quark tensor charges of the nucleon. The precision mapping of TMDs will also allow a detailed study of the quark orbital motion and its dynamics.

  2. An Overview of Longitudinal Spin Structure Measurements from JLab

    SciTech Connect

    Sulkosky, Vincent A.

    2013-08-01

    Jefferson Lab is currently one of the facilities leading the investigation of the spin structure of the nucleon. Over the past 15 years, several high precision measurements have been completed, extending our knowledge of the polarized structure functions g{sub 1} and g{sub 2} down to Q{sup 2} = 0.02 GeV{sup 2}. In particular, the low-Q{sup 2} range ({<=} 0.1 GeV{sup 2}) from these data allows us to make a benchmark-check of Chiral Perturbation theory ({chi}PT). Previous results for the moments of the spin structure functions in this region have shown mixed agreement. For {Gamma}{sub 1}, the first moment of g{sub 1}, we find good consistency between data and theory. However, we have seen a surprisingly large discrepancy with {chi}PT calculations for the {delta}{sub LT} spin polarizability on the neutron, which is significantly less sensitive to the {Delta}-resonance contribution. These proceedings will discuss the recent experimental effort at low Q{sup 2} from Jefferson Lab, including a discussion of preliminary results on the neutron. The new results on the neutron still show a sizeable discrepancy between data and theory. However, new calculations show improved agreement with data for some observables. In addition, new proton data for g{sub 2} is also expected to help resolve the disagreement for {delta}{sub LT}.

  3. Nucleon structure functions and longitudinal spin asymmetries in the chiral quark constituent model

    NASA Astrophysics Data System (ADS)

    Dahiya, Harleen; Randhawa, Monika

    2016-06-01

    We have analyzed the phenomenological dependence of the spin independent (F1p ,n and F2p ,n) and the spin dependent (g1p ,n) structure functions of the nucleon on the Bjorken scaling variable x using the unpolarized distribution functions of the quarks q (x ) and the polarized distribution functions of the quarks Δ q (x ) respectively. The chiral constituent quark model, which is known to provide a satisfactory explanation of the proton spin crisis and related issues in the nonperturbative regime, has been used to compute explicitly the valence and sea quark flavor distribution functions of p and n . In light of the improved precision of the world data, the p and n longitudinal spin asymmetries [A1p(x ) and A1n(x )] have been calculated. The implication of the presence of the sea quarks has been discussed for the ratio of polarized to unpolarized quark distribution functions for up and down quarks in the p and n Δ/up(x ) up(x ) , Δ/dp(x ) dp(x ) , Δ/un(x ) un(x ) , and Δ/dn(x ) dn(x ) . The ratio of the n and p structure functions Rn p(x )=F/2n(x ) F2p(x ) has also been presented. The results have been compared with the recent available experimental observations. The results on the spin sum rule have also been included and compared with data and other recent approaches.

  4. Longitudinal spin fluctuations in nickel

    SciTech Connect

    Boeni, P. , Villigen ); Martinez, J.L. ); Tranquada, J.M. )

    1989-10-10

    The longitudinal and transverse spin fluctuations in Ni have been measured below {Tc} by means of polarized neutron scattering in the momentum range 0.06 < q < 0.18 {angstrom}{sup -1}. In transverse scans spin wave peaks at E{sub q} = Dq{sup 2} appear as expected from early measurements performed with unpolarized neutrons. The longitudinal magnetic scattering {sub {chi}L}(q, E), on the other hand, is quasielastic without any signature of inelastic peaks near E{sub q}. The q and T dependences of {sub {chi}L}(q, E) resemble the paramagnetic scattering above {Tc}, i.e., the linewidth is roughly proportional to q{sup 2.5} and the integrated intensity I(q) is proportional to (q{sup 2} + {kappa}{sub z}{sup 2}){sup -1}. 8 refs., 3 figs.

  5. Measurement of the longitudinal deuteron spin-structure function in deep-inelastic scattering

    SciTech Connect

    Bauer, J.M.

    1996-09-01

    Experiment E143 at SLAC performed deep-inelastic scattering measurements with polarized electrons incident on polarized protons and deuterons. The data for the beam energy of 29 GeV cover the kinematical range of x{sub Bj} > 0.03 and 1 < Q{sup 2} < 12 GeV{sup 2}. From these data, the spin-dependent structure functions g{sub 1} were determined. This dissertation describes the experiment and its analysis and discusses the results. The measured integral of g{sub 1}{sup d} over x from x = 0 to x = 1 is {Gamma}{sub 1}{sup d} = 0.046 {+-} 0.003 (stat){+-}0.004 (syst) at Q{sup 2} = 3 GeV{sup 2} and disagrees by more than three standard deviations with the prediction of the Ellis-Jaffe, sum rule. The data suggest that the quark contribution to the nucleon helicity is 0.35 {+-} 0.05. From the proton data of the same experiment, the integral over the proton spin-structure functional g{sub 1}{sup d} was determined to be {Gamma}{sub 1}{sup p} = 0.127 {+-} 0.003(stat){+-}0.008(syst). By Combining the deuteron data with the proton data, the integral {Gamma}{sub 1}{sup n} was extracted as {minus}0.027 {+-} 0.008 (stat){+-}0.010 (syst). The integral {Gamma}{sub 1}{sup p} {minus} {Gamma}{sub 1}{sup n} is 0.154{+-}0.010(stat) {+-}0.016 (syst) according to the E143 analysis. This result agrees with the important Bjorken sum rule of 0.171 {+-} 0.009 at Q{sup 2} = 3 GeV{sup 2} within less than one standard deviation. Furthermore, results of a separate analysis involving GLAP evolution equations are shown. Data were also collected for beam energies of 16.2 and 9.7 GeV, Results for g{sub 1} at these energies are presented.

  6. Results on longitudinal spin physics at COMPASS

    NASA Astrophysics Data System (ADS)

    Wilfert, Malte

    2016-03-01

    The COMPASS experiment at the CERN SPS has taken data on deep inelastic scattering of polarised muons on a polarised NH3 target in 2007 and 2011 and on a polarised LiD target in 2002-2004 and 2006. The new results on the longitudinal double spin asymmetry A1p and the spin-dependent structure function g1p obtained from the 2011 data set are presented. These results are used in a NLO QCD fit to the world data to obtain the polarised parton distributions. Also an update of the results on the Bjorken sum rule, connecting the integral of the non-singlet spin-dependent structure function with the ratio of the weak coupling constants, will be given. Direct access to the gluon polarisation is possible via the photon gluon fusion process in semi-inclusive deep inelastic scattering. This process is studied using the pT dependence of charged hadron asymmetries. The latest results indicate a positive gluon polarisation in the kinematic region of COMPASS

  7. Evaluation of thermal gradients in longitudinal spin Seebeck effect measurements

    NASA Astrophysics Data System (ADS)

    Sola, A.; Kuepferling, M.; Basso, V.; Pasquale, M.; Kikkawa, T.; Uchida, K.; Saitoh, E.

    2015-05-01

    In the framework of the longitudinal spin Seebeck effect (LSSE), we developed an experimental setup for the characterization of LSSE devices. This class of device consists in a layered structure formed by a substrate, a ferrimagnetic insulator (YIG) where the spin current is thermally generated, and a paramagnetic metal (Pt) for the detection of the spin current via the inverse spin-Hall effect. In this kind of experiments, the evaluation of a thermal gradient through the thin YIG layer is a crucial point. In this work, we perform an indirect determination of the thermal gradient through the measurement of the heat flux. We developed an experimental setup using Peltier cells that allow us to measure the heat flux through a given sample. In order to test the technique, a standard LSSE device produced at Tohoku University was measured. We find a spin Seebeck SSSE coefficient of 2.8 × 10 - 7 V K-1.

  8. Spin structure functions

    SciTech Connect

    Jian-ping Chen, Alexandre Deur, Sebastian Kuhn, Zein-eddine Meziani

    2011-06-01

    Spin-dependent observables have been a powerful tool to probe the internal structure of the nucleon and to understand the dynamics of the strong interaction. Experiments involving spin degrees of freedom have often brought out surprises and puzzles. The so-called "spin crisis" in the 1980s revealed the limitation of naive quark-parton models and led to intensive worldwide efforts, both experimental and theoretical, to understand the nucleon spin structure. With high intensity and high polarization of both the electron beam and targets, Jefferson Lab has the world's highest polarized luminosity and the best figure-of-merit for precision spin structure measurements. It has made a strong impact in this subfield of research. This chapter will highlight Jefferson Lab's unique contributions in the measurements of valence quark spin distributions, in the moments of spin structure functions at low to intermediate Q2, and in the transverse spin structure.

  9. Evaluation of thermal gradients in longitudinal spin Seebeck effect measurements

    SciTech Connect

    Sola, A. Kuepferling, M.; Basso, V.; Pasquale, M.; Kikkawa, T.; Uchida, K.; Saitoh, E.

    2015-05-07

    In the framework of the longitudinal spin Seebeck effect (LSSE), we developed an experimental setup for the characterization of LSSE devices. This class of device consists in a layered structure formed by a substrate, a ferrimagnetic insulator (YIG) where the spin current is thermally generated, and a paramagnetic metal (Pt) for the detection of the spin current via the inverse spin-Hall effect. In this kind of experiments, the evaluation of a thermal gradient through the thin YIG layer is a crucial point. In this work, we perform an indirect determination of the thermal gradient through the measurement of the heat flux. We developed an experimental setup using Peltier cells that allow us to measure the heat flux through a given sample. In order to test the technique, a standard LSSE device produced at Tohoku University was measured. We find a spin Seebeck S{sub SSE} coefficient of 2.8×10{sup −7} V K{sup −1}.

  10. Longitudinal spin Seebeck effect: from fundamentals to applications.

    PubMed

    Uchida, K; Ishida, M; Kikkawa, T; Kirihara, A; Murakami, T; Saitoh, E

    2014-08-27

    The spin Seebeck effect refers to the generation of spin voltage as a result of a temperature gradient in ferromagnetic or ferrimagnetic materials. When a conductor is attached to a magnet under a temperature gradient, the thermally generated spin voltage in the magnet injects a spin current into the conductor, which in turn produces electric voltage owing to the spin-orbit interaction. The spin Seebeck effect is of increasing importance in spintronics, since it enables direct generation of a spin current from heat and appears in a variety of magnets ranging from metals and semiconductors to insulators. Recent studies on the spin Seebeck effect have been conducted mainly in paramagnetic metal/ferrimagnetic insulator junction systems in the longitudinal configuration in which a spin current flowing parallel to the temperature gradient is measured. This 'longitudinal spin Seebeck effect' (LSSE) has been observed in various sample systems and exclusively established by separating the spin-current contribution from extrinsic artefacts, such as conventional thermoelectric and magnetic proximity effects. The LSSE in insulators also provides a novel and versatile pathway to thermoelectric generation in combination of the inverse spin-Hall effects. In this paper, we review basic experiments on the LSSE and discuss its potential thermoelectric applications with several demonstrations. PMID:25105889

  11. Magnon-driven longitudinal spin Seebeck effect in F | N and N | F | N structures: Role of asymmetric in-plane magnetic anisotropy

    NASA Astrophysics Data System (ADS)

    Chotorlishvili, L.; Toklikishvili, Z.; Etesami, S. R.; Dugaev, V. K.; Barnaś, J.; Berakdar, J.

    2015-12-01

    The influence of an asymmetric in-plane magnetic anisotropy Kx ≠Ky on the thermally activated spin current is studied theoretically for two different systems: (i) the F | N system consisting of a ferromagnetic insulator (F) in a direct contact with a nonmagnetic metal (N) and (ii) the sandwich structure N | F | N consisting of a ferromagnetic insulating part sandwiched between two nonmagnetic metals. It is shown that when the difference between the temperatures of the two nonmagnetic metals in a N | F | N structure is not large, the spin pumping currents from the magnetic part to the nonmagnetic ones are equal in amplitude and have opposite directions, so only the spin torque current contributes to the total spin current. The spin current flows then from the nonmagnetic metal with the higher temperature to the nonmagnetic metal having a lower temperature. Its amplitude varies linearly with the difference in temperatures. In addition, we have found that if the magnetic anisotropy is in the layer plane, then the spin current increases with the magnon temperature, while in the case of an out-of-plane magnetic anisotropy the spin current decreases when the magnon temperature enhances. Enlarging the difference between the temperatures of the nonmagnetic metals, the linear response becomes important, as confirmed by analytical expressions inferred from the Fokker-Planck approach and by the results obtained upon a full numerical integration of the stochastic Landau-Lifshitz-Gilbert equation.

  12. Highlights of Spin Study at JLab Hall A: Longitudinal and Transverse

    SciTech Connect

    Chen, J. P.

    2011-12-14

    Spin-dependent observables have been a powerful tool to probe the internal structure of the nucleon and to understand the dynamics of the strong interaction. Experiments involving spin degrees of freedom have lead to numerous surprises, puzzles and discoveries. The so called ''spin crisis'' in the 1980s revealed the limitation of naive quark-parton models and led to intensive worldwide efforts, both experimental and theoretical, to understand the nucleon spin structure. The nucleon spin structrue study has grown from mainly on the longitudinal spin in the last thirty years to recently rapidly increasing interests on the transverse spin. With high intensity and high polarization of both the electron beam and targets, JLab has the world's highest polarized luminosity and the best figure-of-merit for precision spin structure measurements. It has made a strong impact in this subfield of research. This proceeding will highlight JLab Hall A's study in the measurements of the moments of spin structure functions at low-to-intermediate Q{sup 2} and in the transverse spin structure.

  13. Highlights of Spin Study at JLab Hall A: Longitudinal and Transverse

    SciTech Connect

    Jian-Ping Chen

    2011-12-01

    Spin-dependent observables have been a powerful tool to probe the internal structure of the nucleon and to understand the dynamics of the strong interaction. Experiments involving spin degrees of freedom have lead to numerous surprises, puzzles and discoveries. The so called 'spin crisis' in the 1980s revealed the limitation of naive quark-parton models and led to intensive worldwide efforts, both experimental and theoretical, to understand the nucleon spin structure. The nucleon spin structrue study has grown frommainly on the longitudinal spin in the last thirty years to recently rapidly increasing interests on the transverse spin.With high intensity and high polarization of both the electron beam and targets, JLab has the world's highest polarized luminosity and the best figure-of-merit for precision spin structure measurements. It has made a strong impact in this subfield of research. This proceeding will highlight JLab Hall A's study in the measurements of the moments of spin structure functions at low-to-intermediate Q2 and in the transverse spin structure.

  14. Nucleon spin structure

    NASA Astrophysics Data System (ADS)

    Zhu, Wei; Ruan, Jianhong

    2015-10-01

    This paper contains three parts relating to the nucleon spin structure in a simple picture of the nucleon: (i) The polarized gluon distribution in the proton is dynamically predicted starting from a low scale by using a nonlinear quantum chromodynamics (QCD) evolution equation — the Dokshitzer-Gribov-Lipatov-Altarelli-Paris (DGLAP) equation with the parton recombination corrections, where the nucleon is almost consisted only of valence quarks. We find that the contribution of the gluon polarization to the nucleon spin structure is much larger than the predictions of most other theories. This result suggests that a significant orbital angular momentum of the gluons is required to balance the gluon spin momentum. (ii) The spin structure function g1p of the proton is studied, where the perturbative evolution of parton distributions and nonperturbative vector meson dominance (VMD) model are used. We predict g1p asymptotic behavior at small x from lower Q2 to higher Q2. The results are compatible with the data including the early HERA estimations and COMPASS new results. (iii) The generalized Gerasimov-Drell-Hearn (GDH) sum rule is understood based on the polarized parton distributions of the proton with the higher twist contributions. A simple parameterized formula is proposed to clearly present the contributions of different components in the proton to Γ 1p(Q2). The results suggest a possible extended objects with size 0.2-0.3 fm inside the proton.

  15. Magnon spin-current theory for the longitudinal spin-Seebeck effect

    NASA Astrophysics Data System (ADS)

    Rezende, S. M.; Rodríguez-Suárez, R. L.; Cunha, R. O.; Rodrigues, A. R.; Machado, F. L. A.; Fonseca Guerra, G. A.; Lopez Ortiz, J. C.; Azevedo, A.

    2014-01-01

    We present a theoretical model for the longitudinal spin-Seebeck effect (LSSE) in bilayers made of a ferromagnetic insulator (FMI), such as yttrium iron garnet (YIG), and a normal metal (NM), such as platinum (Pt), that relies on the bulk magnon spin current created by the temperature gradient across the thickness of the FMI. We show that the spin current pumped into the NM layer by the magnon accumulation in the FMI provides continuity of the spin current at the FMI/NM interface and is essential for the existence of the longitudinal spin-Seebeck effect. The results of the theory are in good agreement with experimental data for the variation of the LSSE with the sample temperature and with the FMI layer thickness in YIG/Pt bilayers.

  16. Generalized longitudinal susceptibility for magnetic monopoles in spin ice

    PubMed Central

    Bramwell, Steven T.

    2012-01-01

    The generalized longitudinal susceptibility χ(q,ω) affords a sensitive measure of the spatial and temporal correlations of magnetic monopoles in spin ice. Starting with the monopole model, a mean field expression for χ(q,ω) is derived as well as expressions for the mean square longitudinal field and induction at a point. Monopole motion is shown to be strongly correlated, and both spatial and temporal correlations are controlled by the dimensionless monopole density x which defines the ratio of the magnetization relaxation rate and the monopole hop rate. Thermal effects and spin-lattice relaxation are also considered. The derived equations are applicable in the temperature range where the Wien effect for magnetic monopoles is negligible. They are discussed in the context of existing theories of spin ice and the following experimental techniques: DC and AC magnetization, neutron scattering, neutron spin echo and longitudinal and transverse field μSR. The monopole theory is found to unify diverse experimental results, but several discrepancies between theory and experiment are identified. One of these, concerning the neutron scattering line shape, is explained by means of a phenomenological modification to the theory. PMID:23166378

  17. Spin transport in non-magnetic nano-structures induced by non-local spin injection

    NASA Astrophysics Data System (ADS)

    Idzuchi, Hiroshi; Fukuma, Yasuhiro; Otani, YoshiChika

    2015-04-01

    We review our recent achievements on optimization of spin injection from ferromagnetic into non-magnetic metals and characterization of spin transport properties in the non-magnetic nano-structures. We have realized the efficient spin injection by solving spin resistance mismatch problem in spin diffusion process across the interface between ferromagnetic and nonmagnetic metals. We analyzed temperature dependent spin relaxation length and time in Ag within the framework of the Elliot-Yafet mechanism based on spin-orbit interaction and momentum relaxation. The spin relaxation length in a light metal Mg is found comparable to that of Ag due to its peculiar electronic band structure in which so called spin-hotspots dramatically enhance spin relaxation. Spin relaxation properties in various metals are also quantitatively discussed. We employed commonly used Hanle effect measurements to characterize spin relaxation of spin current and reexamined both theoretically and experimentally the effect of spin absorption at the interface. The affected spatial profile of chemical potential due to the longitudinal and transverse spin absorption results in the broadened Hanle curve. All the Hanle curves both in metallic and semi-conductive materials including graphene fall into the universal scaling plot. Anatomy of spin injection properties of the junction and spin transport properties in non-magnetic metal is shown in tables.

  18. Longitudinal spin separation of light and its performance in three-dimensionally controllable spin-dependent focal shift

    PubMed Central

    Liu, Sheng; Li, Peng; Zhang, Yi; Gan, Xuetao; Wang, Meirong; Zhao, Jianlin

    2016-01-01

    Spin Hall effect of light, which is normally explored as a transverse spin-dependent separation of a light beam, has attracted enormous research interests. However, it seems there is no indication for the existence of the longitudinal spin separation of light. In this paper, we propose and experimentally realize the spin separation along the propagation direction by modulating the Pancharatnam-Berry (PB) phase. Due to the spin-dependent divergence and convergence determined by the PB phase, a focused Gaussian beam could split into two opposite spin states, and focuses at different distances, representing the longitudinal spin separation. By combining this longitudinal spin separation with the transverse one, we experimentally achieve the controllable spin-dependent focal shift in three dimensional space. This work provides new insight on steering the spin photons, and is expected to explore novel applications of optical trapping, manipulating, and micromachining with higher degree of freedom. PMID:26882995

  19. Longitudinal spin separation of light and its performance in three-dimensionally controllable spin-dependent focal shift.

    PubMed

    Liu, Sheng; Li, Peng; Zhang, Yi; Gan, Xuetao; Wang, Meirong; Zhao, Jianlin

    2016-01-01

    Spin Hall effect of light, which is normally explored as a transverse spin-dependent separation of a light beam, has attracted enormous research interests. However, it seems there is no indication for the existence of the longitudinal spin separation of light. In this paper, we propose and experimentally realize the spin separation along the propagation direction by modulating the Pancharatnam-Berry (PB) phase. Due to the spin-dependent divergence and convergence determined by the PB phase, a focused Gaussian beam could split into two opposite spin states, and focuses at different distances, representing the longitudinal spin separation. By combining this longitudinal spin separation with the transverse one, we experimentally achieve the controllable spin-dependent focal shift in three dimensional space. This work provides new insight on steering the spin photons, and is expected to explore novel applications of optical trapping, manipulating, and micromachining with higher degree of freedom. PMID:26882995

  20. Bulk magnon spin current theory for the longitudinal spin Seebeck effect

    NASA Astrophysics Data System (ADS)

    Rezende, S. M.; Rodríguez-Suárez, R. L.; Cunha, R. O.; López Ortiz, J. C.; Azevedo, A.

    2016-02-01

    The longitudinal spin Seebeck effect (LSSE) consists in the generation of a spin current parallel to a temperature gradient applied across the thickness of a bilayer made of a ferromagnetic insulator (FMI), such as yttrium iron garnet (YIG), and a metallic layer (ML) with strong spin orbit coupling, such as platinum. The LSSE is usually detected by a DC voltage generated along the ML due to the conversion of the spin current into a charge current perpendicular to the static magnetic field by means of the inverse spin Hall effect. Here we present a model for the LSSE that relies on the bulk magnon spin current created by the temperature gradient across the thickness of the FMI. We show that the spin current pumped into the metallic layer by the magnon accumulation in the FMI provides continuity of the spin current at the FMI/ML interface and is essential for the existence of the LSSE. The results of the theory are in good agreement with experimental LSSE data in YIG/Pt bilayers on the variation of the DC voltage with the sample temperature, with the FMI layer thickness and with the intensity of high magnetic fields.

  1. Recent Results from the Jet Longitudinal Spin Program at STAR

    SciTech Connect

    Igo, G.

    2009-03-23

    We report STAR's preliminary measurement of the inclusive jet longitudinal spin asymmetry A{sub LL} using data from the RHIC 2006 run. The 2006 data set was taken with 200 GeV polarized proton-proton collisions and represents 4.7 pb{sup -1} of data. Typical beam polarizations were {approx}55-60%. The data are compared with theoretical calculations of A{sub LL} based on various models of the polarized parton distribution functions in the nucleon. STAR inclusive jet A{sub LL} measurements from the RHIC 2005 run are also discussed.

  2. Spin Hall Effect in Doped Semiconductor Structures

    NASA Astrophysics Data System (ADS)

    Tse, Wang-Kong; Das Sarma, Sankar

    2006-03-01

    We present a microscopic theory of the extrinsic spin Hall effect based on the diagrammatic perturbation theory. Side-jump (SJ) and skew-scattering (SS) contributions are explicitly taken into account to calculate the spin Hall conductivity, and we show their effects scale as σxy^SJ/σxy^SS ˜(/τ)/ɛF, where τ being the transport relaxation time. Motivated by recent experimental work we apply our theory to n-doped and p-doped 3D and 2D GaAs structures, obtaining analytical formulas for the SJ and SS contributions. Moreover, the ratio of the spin Hall conductivity to longitudinal conductivity is found as σs/σc˜10-3-10-4, in reasonable agreement with the recent experimental results of Kato et al. [Science 306, 1910 (2004)] in n-doped 3D GaAs system.

  3. Charge and Paramagnetic Spin Susceptibilities of Doped Gapped Graphene-Like Structures

    NASA Astrophysics Data System (ADS)

    Rezania, H.; Naseri, Y.

    2016-06-01

    We address spin polarization dependence of dynamical charge and spin susceptibilities of doped gapped graphene-like structures in the context of tight binding model Hamiltonian. The frequency behavior of both longitudinal and transverse spin susceptibilities has been calculated via calculating correlation function of spin density operators. Our results show the increase of electronic concentration corresponding to chemical potential leads to enhance the intensity of charge spectral function. We also show that longitudinal spin susceptibility reduces at fixed frequency with gap parameter associated with on-site energy difference between two types of sublattice atoms. Furthermore, the resonance peak in longitudinal spin susceptibility goes to higher frequencies with gap parameter. The effect of magnetization on the longitudinal spin susceptibility indicates two different behaviors depending on frequency region. Finally, the effects of magnetization and gap parameter on the frequency behavior of transverse spin susceptibility have been studied in details.

  4. Longitudinal target-spin asymmetries for deeply virtual compton scattering.

    PubMed

    Seder, E; Biselli, A; Pisano, S; Niccolai, S; Smith, G D; Joo, K; Adhikari, K; Amaryan, M J; Anderson, M D; Anefalos Pereira, S; Avakian, H; Battaglieri, M; Bedlinskiy, I; Bono, J; Boiarinov, S; Bosted, P; Briscoe, W; Brock, J; Brooks, W K; Bültmann, S; Burkert, V D; Carman, D S; Carlin, C; Celentano, A; Chandavar, S; Charles, G; Colaneri, L; Cole, P L; Contalbrigo, M; Crabb, D; Crede, V; D'Angelo, A; Dashyan, N; De Vita, R; De Sanctis, E; Deur, A; Djalali, C; Doughty, D; Dupre, R; El Fassi, L; Elouadrhiri, L; Eugenio, P; Fedotov, G; Fegan, S; Filippi, A; Fleming, J A; Fradi, A; Garillon, B; Garçon, M; Gevorgyan, N; Ghandilyan, Y; Giovanetti, K L; Girod, F X; Goetz, J T; Gohn, W; Gothe, R W; Griffioen, K A; Guegan, B; Guidal, M; Guo, L; Hafidi, K; Hakobyan, H; Hanretty, C; Harrison, N; Hattawy, M; Hirlinger Saylor, N; Holtrop, M; Hughes, S M; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Isupov, E L; Jo, H S; Joosten, S; Keith, C D; Keller, D; Khachatryan, G; Khandaker, M; Kim, A; Kim, W; Klein, A; Klein, F J; Koirala, S; Kubarovsky, V; Kuhn, S E; Lenisa, P; Livingston, K; Lu, H Y; MacGregor, I J D; Markov, N; Mayer, M; McKinnon, B; Meekins, D G; Mineeva, T; Mirazita, M; Mokeev, V; Montgomery, R; Moody, C I; Moutarde, H; Movsisyan, A; Munoz Camacho, C; Nadel-Turonski, P; Niculescu, I; Osipenko, M; Ostrovidov, A I; Paolone, M; Pappalardo, L L; Park, K; Park, S; Pasyuk, E; Peng, P; Phelps, W; Pogorelko, O; Price, J W; Prok, Y; Protopopescu, D; Puckett, A J R; Ripani, M; Rizzo, A; Rosner, G; Rossi, P; Roy, P; Sabatié, F; Salgado, C; Schott, D; Schumacher, R A; Senderovich, I; Simonyan, A; Skorodumina, I; Sokhan, D; Sparveris, N; Stepanyan, S; Stoler, P; Strakovsky, I I; Strauch, S; Sytnik, V; Taiuti, M; Tang, W; Tian, Y; Ungaro, M; Voskanyan, H; Voutier, E; Walford, N K; Watts, D P; Wei, X; Weinstein, L B; Wood, M H; Zachariou, N; Zana, L; Zhang, J; Zonta, I

    2015-01-23

    A measurement of the electroproduction of photons off protons in the deeply inelastic regime was performed at Jefferson Lab using a nearly 6 GeV electron beam, a longitudinally polarized proton target, and the CEBAF Large Acceptance Spectrometer. Target-spin asymmetries for ep→e^{'}p^{'}γ events, which arise from the interference of the deeply virtual Compton scattering and the Bethe-Heitler processes, were extracted over the widest kinematics in Q^{2}, x_{B}, t, and ϕ, for 166 four-dimensional bins. In the framework of generalized parton distributions, at leading twist the t dependence of these asymmetries provides insight into the spatial distribution of the axial charge of the proton, which appears to be concentrated in its center. These results also bring important and necessary constraints for the existing parametrizations of chiral-even generalized parton distributions. PMID:25658994

  5. Longitudinal target-spin asymmetries for deeply virtual Compton scattering

    SciTech Connect

    Seder, E.; Biselli, A.; Pisano, S.; Niccolai, S.; Smith, G. D.; Joo, K.; Adhikari, K.; Amaryan, M. J.; Anderson, M. D.; Anefalos Pereira, S.; Avakian, H.; Battaglieri, M.; Bedlinskiy, I.; Bono, J.; Boiarinov, S.; Bosted, P.; Briscoe, W.; Brock, J.; Brooks, W. K.; Bültmann, S.; Burkert, V. D.; Carman, D. S.; Carlin, C.; Celentano, A.; Chandavar, S.; Charles, G.; Colaneri, L.; Cole, P. L.; Contalbrigo, M.; Crabb, D.; Crede, V.; D’Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Doughty, D.; Dupre, R.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Filippi, A.; Fleming, J. A.; Fradi, A.; Garillon, B.; Garçon, M.; Gevorgyan, N.; Ghandilyan, Y.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Gohn, W.; Gothe, R. W.; Griffioen, K. A.; Guegan, B.; Guidal, M.; Guo, L.; Hafidi, K.; Hakobyan, H.; Hanretty, C.; Harrison, N.; Hattawy, M.; Hirlinger Saylor, N.; Holtrop, M.; Hughes, S. M.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jo, H. S.; Joosten, S.; Keith, C. D.; Keller, D.; Khachatryan, G.; Khandaker, M.; Kim, A.; Kim, W.; Klein, A.; Klein, F. J.; Koirala, S.; Kubarovsky, V.; Kuhn, S. E.; Lenisa, P.; Livingston, K.; Lu, H. Y.; MacGregor, I. J. D.; Markov, N.; Mayer, M.; McKinnon, B.; Meekins, D. G.; Mineeva, T.; Mirazita, M.; Mokeev, V.; Montgomery, R.; Moody, C. I.; Moutarde, H.; Movsisyan, A.; Munoz Camacho, C.; Nadel-Turonski, P.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Paolone, M.; Pappalardo, L. L.; Park, K.; Park, S.; Pasyuk, E.; Peng, P.; Phelps, W.; Pogorelko, O.; Price, J. W.; Prok, Y.; Protopopescu, D.; Puckett, A. J. R.; Ripani, M.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Sabatié, F.; Salgado, C.; Schott, D.; Schumacher, R. A.; Senderovich, I.; Simonyan, A.; Skorodumina, I.; Sokhan, D.; Sparveris, N.; Stepanyan, S.; Stoler, P.; Strakovsky, I. I.; Strauch, S.; Sytnik, V.; Taiuti, M.; Tang, W.; Tian, Y.; Ungaro, M.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Watts, D. P.; Wei, X.; Weinstein, L. B.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhang, J.; Zonta, I.

    2015-01-22

    A measurement of the electroproduction of photons off protons in the deeply inelastic regime was performed at Jefferson Lab using a nearly 6-GeV electron beam, a longitudinally polarized proton target and the CEBAF Large Acceptance Spectrometer. Target-spin asymmetries for ep → e'p'y events, which arise from the interference of the deeply virtual Compton scattering and the Bethe-Heitler processes, were extracted over the widest kinematics in Q2, xB, t and Φ, for 166 four-dimensional bins. In the framework of Generalized Parton Distributions (GPDs), at leading twist the t dependence of these asymmetries provides insight on the spatial distribution of the axial charge of the proton, which appears to be concentrated in its center. In conclusion, these results bring important and necessary constraints for the existing parametrizations of chiral-even GPDs.

  6. Longitudinal target-spin asymmetries for deeply virtual Compton scattering

    DOE PAGESBeta

    Seder, E.; Biselli, A.; Pisano, S.; Niccolai, S.; Smith, G. D.; Joo, K.; Adhikari, K.; Amaryan, M. J.; Anderson, M. D.; Anefalos Pereira, S.; et al

    2015-01-22

    A measurement of the electroproduction of photons off protons in the deeply inelastic regime was performed at Jefferson Lab using a nearly 6-GeV electron beam, a longitudinally polarized proton target and the CEBAF Large Acceptance Spectrometer. Target-spin asymmetries for ep → e'p'y events, which arise from the interference of the deeply virtual Compton scattering and the Bethe-Heitler processes, were extracted over the widest kinematics in Q2, xB, t and Φ, for 166 four-dimensional bins. In the framework of Generalized Parton Distributions (GPDs), at leading twist the t dependence of these asymmetries provides insight on the spatial distribution of the axialmore » charge of the proton, which appears to be concentrated in its center. In conclusion, these results bring important and necessary constraints for the existing parametrizations of chiral-even GPDs.« less

  7. Design of Spin Polarization Analyzer using Transverse-Longitudinal Correlation in Resistivities Induced by Spin-Orbit Interaction

    NASA Astrophysics Data System (ADS)

    Sakai, Masamichi; Kakizaki, Koichi; Hasegawa, Shigehiko; Kitajima, Akira; Oshima, Akihiro; Awano, Hiroyuki

    2013-01-01

    We have theoretically studied a methodology for the measurement of the degree of spin polarization (P) in metals as well as semiconductors. Our principle is based on the correlation existing between transverse resistivity (ρyx) and longitudinal resistivity (ρxx), both influenced by transverse scattering due to a spin-orbit interaction (SOI) as well as longitudinal scattering due to usual mechanisms. Our spin polarization analyzer employs an unknown polarization conductor as a source electrode from which spin-polarized electrons are injected into a nonmagnetic (NM) channel region. The channel length is set to be much smaller than its spin diffusion length so that ρyx and ρxx in the NM region, both complementarily influenced by carrier spin polarization, would be measured to obtain the P value. Also, application to OR and XOR logic gates are discussed on the basis of our spin polarization analyzer.

  8. Drell-Yan Cross Section and Longitudinal Double Spin Asymmetry in the PHENIX Experiment at RHIC

    NASA Astrophysics Data System (ADS)

    Perera, Gonaduwage

    2015-10-01

    Analysis of the Drell-Yan process in high energy polarized proton-proton collisions is a unique method for probing the proton spin structure. Measurement of the longitudinal double spin asymmetry (ALL) in the Drell-Yan process provides clean access to the anti-quark helicity distributions without involving quark fragmentation functions. In the PHENIX experiment at RHIC, the Forward Silicon Vertex Detector (FVTX), together with forward muon spectrometers, allows us to study the Drell-Yan process by detecting the muon pairs in the forward region (1 . 2 < | η | < 2 . 4) while also suppressing backgrounds due to heavy-flavor production. In this talk we present the status of the Drell-Yan cross-section and ALL measurement for the intermediate mass region (4 GeV < M < 8 GeV) using the RHIC 2013 data of proton-proton collisions at a center of mass energy of 510 GeV.

  9. Longitudinal surface structures (flowstripes) on Antarctic glaciers

    NASA Astrophysics Data System (ADS)

    Glasser, N. F.; Gudmundsson, G. H.

    2012-03-01

    Longitudinal surface structures ("flowstripes") are common on many glaciers but their origin and significance are poorly understood. In this paper we present observations of the development of these longitudinal structures from four different Antarctic glacier systems; the Lambert Glacier/Amery Ice Shelf area, the Taylor and Ferrar Glaciers in the Ross Sea sector, Crane and Jorum Glaciers (ice-shelf tributary glaciers) on the Antarctic Peninsula, and the onset zone of a tributary to the Recovery Glacier Ice Stream in the Filchner Ice Shelf area. Mapping from optical satellite images demonstrates that longitudinal surface structures develop in two main situations: (1) as relatively wide flow stripes within glacier flow units and (2) as relatively narrow flow stripes where there is convergent flow around nunataks or at glacier confluence zones. Our observations indicate that the confluence features are narrower, sharper, and more clearly defined features. They are characterised by linear troughs or depressions on the ice surface and are much more common than the former type. Longitudinal surface structures within glacier flow units have previously been explained as the surface expression of localised bed perturbations but a universal explanation for those forming at glacier confluences is lacking. Here we propose that these features are formed at zones of ice acceleration and extensional flow at glacier confluences. We provide a schematic model for the development of longitudinal surface structures based on extensional flow that can explain their ridge and trough morphology as well as their down-ice persistence.

  10. Spin structure of the proton

    SciTech Connect

    Nathan Isgur

    1995-08-01

    In these lectures the author argues that their response to the spin crisis should not be to abandon the naive quark model baby, but rather to allow it to mature. He begin by recalling what a beautiful baby the quark model is via an overview of its successes in spectroscopy, dynamics, and valence spin structure. He also introduces the conservative hypothesis that dynamical q{anti q} pairs are its key missing ingredient. He then discusses dressing the baby. He first shows that it can be clothed in glue without changing its spectroscopic successes. In the process, several dynamical mysteries associated with quark model spectroscopy are potentially explained. Next, he dresses the baby in q{anti q} pairs, first showing that this can be done without compromising the naive quark model's success with either spectroscopy or the OZI rule. Finally, he shows that despite their near invisibility elsewhere, pairs do play an important role in the proton's spin structure by creating an antipolarized q{anti q} sea. In the context of an explicit calculation he demonstrate that it is plausible that the entire ''spin crisis'' arises from this effect.

  11. The Spin Structure Function g2

    SciTech Connect

    Rock, Stephen E.

    2003-02-27

    We have measured the spin structure functions g{sub 2}{sup p} and g{sub 2}{sup d} over the kinematic range 0.02 {le} x {le} 0.8 and 0.7 {le} Q{sup 2} {le} 20 GeV{sup 2} by scattering 29.1 and 32.3 GeV longitudinally polarized electrons from transversely polarized NH{sub 3} and {sup 6}LiD targets. Our measured g{sub 2} approximately follows the twist-2 Wandzura-Wilczek calculation. The twist-3 reduced matrix elements d{sub 2}{sup p} and d{sub 2}{sup n} are less than two standard deviations from zero. The data are inconsistent with the Burkhardt-Cottingham sum rule. The Efremov-Leader-Teryaev integral is consistent with zero within our measured kinematic range.

  12. Longitudinal spin Seebeck effect contribution in transverse spin Seebeck effect experiments in Pt/YIG and Pt/NFO.

    PubMed

    Meier, Daniel; Reinhardt, Daniel; van Straaten, Michael; Klewe, Christoph; Althammer, Matthias; Schreier, Michael; Goennenwein, Sebastian T B; Gupta, Arunava; Schmid, Maximilian; Back, Christian H; Schmalhorst, Jan-Michael; Kuschel, Timo; Reiss, Günter

    2015-01-01

    The spin Seebeck effect, the generation of a spin current by a temperature gradient, has attracted great attention, but the interplay over a millimetre range along a thin ferromagnetic film as well as unintended side effects which hinder an unambiguous detection have evoked controversial discussions. Here, we investigate the inverse spin Hall voltage of a 10 nm thin Pt strip deposited on the magnetic insulators Y3Fe5O12 and NiFe2O4 with a temperature gradient in the film plane. We show characteristics typical of the spin Seebeck effect, although we do not observe the most striking features of the transverse spin Seebeck effect. Instead, we attribute the observed voltages to the longitudinal spin Seebeck effect generated by a contact tip induced parasitic out-of-plane temperature gradient, which depends on material, diameter and temperature of the tip. PMID:26394541

  13. Longitudinal spin Seebeck effect contribution in transverse spin Seebeck effect experiments in Pt/YIG and Pt/NFO

    PubMed Central

    Meier, Daniel; Reinhardt, Daniel; van Straaten, Michael; Klewe, Christoph; Althammer, Matthias; Schreier, Michael; Goennenwein, Sebastian T. B.; Gupta, Arunava; Schmid, Maximilian; Back, Christian H.; Schmalhorst, Jan-Michael; Kuschel, Timo; Reiss, Günter

    2015-01-01

    The spin Seebeck effect, the generation of a spin current by a temperature gradient, has attracted great attention, but the interplay over a millimetre range along a thin ferromagnetic film as well as unintended side effects which hinder an unambiguous detection have evoked controversial discussions. Here, we investigate the inverse spin Hall voltage of a 10 nm thin Pt strip deposited on the magnetic insulators Y3Fe5O12 and NiFe2O4 with a temperature gradient in the film plane. We show characteristics typical of the spin Seebeck effect, although we do not observe the most striking features of the transverse spin Seebeck effect. Instead, we attribute the observed voltages to the longitudinal spin Seebeck effect generated by a contact tip induced parasitic out-of-plane temperature gradient, which depends on material, diameter and temperature of the tip. PMID:26394541

  14. Oblique propagation of longitudinal waves in magnetized spin-1/2 plasmas: Independent evolution of spin-up and spin-down electrons

    SciTech Connect

    Andreev, Pavel A. Kuz’menkov, L.S.

    2015-10-15

    We consider quantum plasmas of electrons and motionless ions. We describe separate evolution of spin-up and spin-down electrons. We present corresponding set of quantum hydrodynamic equations. We assume that plasmas are placed in an uniform external magnetic field. We account different occupation of spin-up and spin-down quantum states in equilibrium degenerate plasmas. This effect is included via equations of state for pressure of each species of electrons. We study oblique propagation of longitudinal waves. We show that instead of two well-known waves (the Langmuir wave and the Trivelpiece–Gould wave), plasmas reveal four wave solutions. New solutions exist due to both the separate consideration of spin-up and spin-down electrons and different occupation of spin-up and spin-down quantum states in equilibrium state of degenerate plasmas.

  15. 46 CFR 154.176 - Longitudinal contiguous hull structure.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Longitudinal contiguous hull structure. 154.176 Section... Equipment Hull Structure § 154.176 Longitudinal contiguous hull structure. (a) The longitudinal contiguous hull structure of a vessel having cargo containment systems without secondary barriers must meet...

  16. 46 CFR 154.176 - Longitudinal contiguous hull structure.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Longitudinal contiguous hull structure. 154.176 Section... Equipment Hull Structure § 154.176 Longitudinal contiguous hull structure. (a) The longitudinal contiguous hull structure of a vessel having cargo containment systems without secondary barriers must meet...

  17. 46 CFR 154.176 - Longitudinal contiguous hull structure.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Longitudinal contiguous hull structure. 154.176 Section... Equipment Hull Structure § 154.176 Longitudinal contiguous hull structure. (a) The longitudinal contiguous hull structure of a vessel having cargo containment systems without secondary barriers must meet...

  18. Spin Structure of the Pion

    SciTech Connect

    Broemmel, D.; Diehl, M.; Goeckeler, M.; Schaefer, A.; Haegler, Ph.; Horsley, R.; Zanotti, J. M.; Nakamura, Y.; Pleiter, D.; Schierholz, G.

    2008-09-19

    We present the first calculation of the transverse spin structure of the pion in lattice QCD. Our simulations are based on two flavors of nonperturbatively improved Wilson fermions, with pion masses as low as 400 MeV in volumes up to (2.1 fm){sup 3} and lattice spacings below 0.1 fm. We find a characteristic asymmetry in the spatial distribution of transversely polarized quarks. This asymmetry is very similar in magnitude to the analogous asymmetry we previously obtained for quarks in the nucleon. Our results support the hypothesis that all Boer-Mulders functions are alike.

  19. Pure spin current in lateral structures

    NASA Astrophysics Data System (ADS)

    Chen, Shuhan

    Spintronics, a frontier academic research area, is advancing rapidly in recent years. It has been chosen as one of the promising candidates for overcoming the obstacles in continuing the "Moore's Law" of the electronics industry. Spintronics employs both spin and charge degrees of freedom of electrons to reduce energy consumption and increase the flexibility of IC design. To achieve this, it is extremely important to understand the generation, transport, and detection of the spin polarized current (spin current). In this work we use a mesoscopic metallic spintronic structure-nonlocal spin valve (NLSV)-for fundamental studies of spintronics. A nonlocal spin valve consists of two ferromagnetic electrodes (a spin injector and a spin detector) bridged by a non-magnetic spin channel. A thin aluminum oxide barrier (~ 2 - 3 nm) has been shown to effectively enhance the spin injection and detection polarizations. We have studied spin injection and detection in these nanoscale structures. Several topics will be discussed in this work. In Chapter 4 we explore spin transport in NLSVs with Ag channels. Substantial spin signals are observed. The temperature dependence of the spin signals indicates long spin diffusion lengths and low surface spin-flip rate in the mesoscopic Ag channels. Chapter 5 will focus on the asymmetric spin absorption across the low-resistance AlOx barriers in NLSVs. This effect allows for a more simplified and efficient detection scheme for the spin accumulation. Then in Chapter 6 we report a large spin signal owing to a highly resistive break-junction. We have also developed a model to describe the spin-charge coupling effect which enables the large spin signal. In the end, Spin Hall Effect (SHE) is investigated in Chapter 7. A mesoscopic Pt film is utilized to inject a spin accumulation into a mesoscopic Cu channel via the SHE. The spin accumulation in Cu can be detected by the nonlocal method. The reciprocal effect -- the inverse Spin Hall Effect - (i

  20. Measurement of the spin structure of the deuteron at COMPASS

    SciTech Connect

    Hannappel, Juergen

    2005-10-06

    A new measurement of the longitudinal spin asymmetry A{sub 1}{sup d} and the spin dependent structure function g{sub 1}{sup d} of the deuteron is presented in the Q2 range from 1GeV2 to 100GeV2 and the x range from 0.004 to 0.7. The data were taken in 2002 and 2003 with the COMPASS experiment at CERN, scattering 160 GeV2 polarised muons off a large polarised 6LiD target. While significantly improving statistical accuracy in the low x region the data agree nicely with previous experiments.

  1. Measurement of the spin-structure function g 2 and the semi-inclusive double-spin asymmetries at HERMES

    NASA Astrophysics Data System (ADS)

    Korotkov, V. A.

    2014-01-01

    A measurement of the virtual-photon asymmetry A 2 and of the spin-structure function g 2 of the proton are presented for the kinematic range of the HERMES experiment carried out at the HERA electron storage ring at DESY. Semi-inclusive longitudinal double-spin asymmetries provide new insight into the valence quark helicity distributions Δ u v and Δ d v.

  2. The Spin Structure of the Proton in the Resonance Region

    SciTech Connect

    Renee Fatemi

    2002-01-01

    Inclusive double spin asymmetries have been measured for {rvec p}({rvec e},e{prime}) using the CLAS detector and a polarized {sup 15}NH{sub 3} target at Jefferson Lab in 1998. The virtual photon asymmetry A{sub 1}, the longitudinal spin structure function, g{sub 1} (x, Q{sup 2}), and the first moment {Gamma}{sub 1}{sup p}, have been extracted for a Q{sup 2} range of 0.15-2.0 GeV{sup 2}. These results provide insight into the low Q{sup 2} evolution of spin dependent asymmetries and structure functions as well as the transition of {Gamma}{sub 1}{sup p} from the photon point, where the Gerasimov, Drell and Hearn Sum Rule is expected to be satisfied, to the deep inelastic region.

  3. Nucleon Resonances Spin Structure - RSS: Experiment 01-006 at Jefferson Lab

    SciTech Connect

    Rondon-Aramayo, Oscar

    2006-07-01

    We have measured the spin structure of the nucleon in the region of the resonances (final state mass W <~ 2 GeV) at intermediate four-momentum transfer Q^2 ~ 1.3 (GeV/c)^2. Double-spin inclusive asymmetries for longitudinally polarized 5.75 GeV electrons incident on longitudinal and transverse solid polarized targets were measured in Jefferson Lab's Hall C. Frozen ammonia and deuterated ammonia were used as the polarized materials. The neutron spin structure is extracted from the proton and deuteron asymmetries. We present new results for the proton measured asymmetries A|| and A[perpendicular] and spin structure functions g_1 and g_2, and preliminary results for the deuteron asymmetries. These are the first measurements of the transverse proton and deuteron spin structure in the resonances. We also report on our measurement of the ratio of the proton electromagnetic form factors with our polarized target.

  4. Nucleon Resonances Spin Structure - RSS: Experiment 01-006 at Jefferson Lab

    SciTech Connect

    Rondon, Oscar A.

    2006-07-11

    We have measured the spin structure of the nucleon in the region of the resonances (final state mass W <{approx} 2 GeV) at intermediate four-momentum transfer Q2 {approx} 1.3 (GeV/c)2. Double-spin inclusive asymmetries for longitudinally polarized 5.75 GeV electrons incident on longitudinal and transverse solid polarized targets were measured in Jefferson Lab's Hall C. Frozen ammonia and deuterated ammonia were used as the polarized materials. The neutron spin structure is extracted from the proton and deuteron asymmetries. We present new results for the proton measured asymmetries A parallel and A perpendicular and spin structure functions g1 and g2, and preliminary results for the deuteron asymmetries. These are the first measurements of the transverse proton and deuteron spin structure in the resonances. We also report on our measurement of the ratio of the proton electromagnetic form factors with our polarized target.

  5. Nucleon spin structure studies at COMPASS

    SciTech Connect

    Marchand, Claude

    2006-02-11

    One of the main goal of the COMPASS experiment at CERN is the study of the spin structure of the nucleon in DIS, by scattering 160 GeV polarized muon beam on a longitudinally (or transversely) polarized 6LiD target. Besides the scattered muon, the particles produced in the deep inelastic scattering are detected by a two stage magnetic spectrometer equipped with state of the art tracking and particle ID detectors.The emphasis of COMPASS muon program is the direct determination of the gluon polarization {delta}G/G, accessed via asymmetries involving photon-gluon fusion mechanism (PGF). Both open charm production (detecting D0's), as well as production of height pT hadron pairs are used to tag PGF. Preliminary results for {delta}G/G based on the analysis of 2002 and 2003 data are shown. In addition, improved measurement of the deuteron structure function g{sub 1}{sup d} at small x, as well as studies of transverse distribution functions in the deuteron by measuring Collins and Sivers azimuthal asymmetries, are reported.

  6. University Spin-Offs in Sweden: A Longitudinal Study

    ERIC Educational Resources Information Center

    Lowegren, Marie; Bengtsson, Lars

    2010-01-01

    There have been few studies on the long-term performance of university spin-offs (USOs). This paper builds on previous empirical research into the performance of USOs and on the resource- based model of USOs. Several research issues are addressed including, in particular, the long-term performance of Swedish USOs, the distribution of the main…

  7. Frozen spin targets in ribosomal structure research.

    PubMed

    Stuhrmann, H B

    1991-01-01

    Polarized neutron scattering strongly depends on nuclear spin polarisation, particularly on proton spin polarisation. A single proton in a deuterated environment then is as efficient as 10 electrons in X-ray anomalous diffraction. Neutron scattering from the nuclear spin label is controlled by the polarisation of neutron spins and nuclear spins. Pure deuteron spin labels and proton spin labels are created by NMR saturation. We report on results obtained from the large subunit of E. coli ribosomes which have been obtained at the research reactor of GKSS using the polarized target facility developed by CERN. The nuclear spins were oriented with respect to an external field by dynamic nuclear polarisation. Proton spin polarisations of more than 80% were obtained in ribosomes at temperatures below 0.5 K. At T = 130 mK the relaxation time of the polarized target is one month (frozen spin target). Polarized small-angle neutron scattering of the in situ structure of rRNA and the total ribosomal protein (TP) has been determined from the frozen spin targets of the large ribosomal subunit, which has been deuterated in the TP and rRNA respectively. The results agree with those from neutron scattering in H2O/D2O mixtures obtained at room temperature. This is a necessary prerequisite for the planned determination of the in situ structure of individual ribosomal proteins and especially of that of ribosome bound mRNA and tRNAs. PMID:1720669

  8. Internal spin structure of the proton from high energy polarized e-p scattering

    SciTech Connect

    Hughes, V.W.; Baum, G.; Bergstroem, M.R.

    1981-02-01

    A review is given of experimental knowledge of the spin dependent structure functions of the proton, which is based on inclusive high energy scattering of longitudinal polarized electrons by longitudinally polarized protons in both the deep inelastic and resonance regions, and includes preliminary results from our most recent SLAC experiment. Implications for scaling, sum rules, models of proton structure, and the hyperfine structure interval in hydrogen are given. Possible future directions of research are indicated.

  9. Understanding the proton's spin structure

    SciTech Connect

    Fred Myhrer; Thomas, Anthony W.

    2010-02-01

    We discuss the tremendous progress that has been towards an understanding of how the spin of the proton is distributed on its quark and gluon constituents. This is a problem that began in earnest twenty years ago with the discovery of the proton "spin crisis" by the European Muon Collaboration. The discoveries prompted by that original work have given us unprecedented insight into the amount of spin carried by polarized gluons and the orbital angular momentum of the quarks.

  10. Structure and spin of the nucleon

    NASA Astrophysics Data System (ADS)

    Avakian, H.

    2014-03-01

    Parton distribution functions, describing longitudinal momentum, helicity and transversity distributions of quarks and gluons, have been recently generalized to account also for transverse degrees of freedom. Two new sets of more general distributions, Transverse Momentum Distributions and Generalized Parton Distributions, were introduced to describe transverse momentum and space distributions of partons. Great progress has been made since then in measurements of different Single Spin Asymmetries (SSAs) in semi-inclusive and hard exclusive processes providing access to TMDs and GPDs, respectively. Facilities world-wide involved in studies of the 3D structure of nucleon include HERMES, COMPASS, BELLE, BaBar, Halls A, B, and C at JLab, and PHENIX and STAR at RHIC (BNL). TMD studies in the Drell-Yan process are also becoming an important part of the program of hadron scattering experiments. Studies of TMDs are also among the main driving forces of the JLab 12-GeV upgrade project, several of the forward upgrade proposals of STAR and PHENIX at RHIC, and future facilities, such as the Electron Ion Collider (EIC), FAIR in Germany, and NICA in Russia. In this contribution we present an overview of the latest developments in studies of parton distributions and discuss newly released results, ongoing activities, as well as some future measurements.

  11. Structure and Spin of the Nucleon

    SciTech Connect

    Avakian, Harut A.

    2014-03-01

    Parton distribution functions, describing longitudinal momentum, helicity and transversity distributions of quarks and gluons, have been recently generalized to account also for transverse degrees of freedom. Two new sets of more general distributions, Transverse Momentum Distributions and Generalized Parton Distributions, were introduced to describe transverse momentum and space distributions of partons. Great progress has been made since then in measurements of different Single Spin Asymmetries (SSAs) in semi-inclusive and hard exclusive processes providing access to TMDs and GPDs, respectively. Facilities world-wide involved in studies of the 3D structure of nucleon include HERMES, COMPASS, BELLE, BaBar, Halls A, B, and C at JLab, and PHENIX and STAR at RHIC (BNL). TMD studies in the Drell-Yan process are also becoming an important part of the program of hadron scattering experiments. Studies of TMDs are also among the main driving forces of the JLab 12-GeV upgrade project, several of the forward upgrade proposals of STAR and PHENIX at RHIC, and future facilities, such as the Electron Ion Collider (EIC), FAIR in Germany, and NICA in Russia. In this contribution we present an overview of the latest developments in studies of parton distributions and discuss newly released results, ongoing activities, as well as some future measurements.

  12. Spin Qubits in Germanium Structures with Phononic Gap

    NASA Technical Reports Server (NTRS)

    Smelyanskiy, V. N.; Vasko, F. T.; Hafiychuk, V. V.; Dykman, M. I.; Petukhov, A. G.

    2014-01-01

    We propose qubits based on shallow donor electron spins in germanium structures with phononic gap. We consider a phononic crystal formed by periodic holes in Ge plate or a rigid cover / Ge layer / rigid substrate structure with gaps approximately a few GHz. The spin relaxation is suppressed dramatically, if the Zeeman frequency omegaZ is in the phononic gap, but an effective coupling between the spins of remote donors via exchange of virtual phonons remains essential. If omegaZ approaches to a gap edge in these structures, a long-range (limited by detuning of omegaZ) resonant exchange interaction takes place. We estimate that ratio of the exchange integral to the longitudinal relaxation rate exceeds 10(exp 5) and lateral scale of resonant exchange 0.1 mm. The exchange contribution can be verified under microwave pumping through oscillations of spin echo signal or through the differential absorption measurements. Efficient manipulation of spins due to the Rabi oscillations opens a new way for quantum information applications.

  13. Spin Structure Function Measurements in Hall C at Jefferson Lab

    SciTech Connect

    Wood, Stephen A.

    2008-11-01

    This presentation introduces the spin structure functions and resonant spin structure, and it discusses the experimental approaches for studying spin structure via polarized electron beam interactions with frozen polarized proton and deuteron targets.

  14. Thermodynamic properties of anisotropic spin ladder in a longitudinal magnetic field

    NASA Astrophysics Data System (ADS)

    Rezania, H.

    2015-08-01

    We address thermodynamic properties of quasi-one dimensional two leg antiferromagnetic ladder in the presence of magnetic field. A generalized bond operator formalism is used to transform the spin model to a hard core bosonic gas. We have implemented Green's function approach to obtain the temperature dependence of spin excitation spectrum in field induced spin polarized phase. The results show energy gap that vanishes at critical magnetic field for fixed values of temperatures. We have also found the temperature dependence of the specific heat and magnetization component in the magnetic field direction for various magnetic field strengths and anisotropies in the Heisenberg interactions on both leg and rung couplings. At low temperatures, the specific heat is found to be monotonically increasing with temperature for magnetic fields in the spin polarized phase region. Furthermore we studied the temperature dependence of the longitudinal magnetization for different magnetic field and anisotropy parameters.

  15. Λ/Λ¯ Longitudinal Spin Transfer from Asymmetric Nucleon s/s¯ Distribution

    NASA Astrophysics Data System (ADS)

    Du, Xiaozhen; Chi, Yujie; Ma, Bo-Qiang

    2016-02-01

    We investigate quark to Λ and Λ¯ longitudinal spin transfers in the light-cone SU(6) quark sepctator-diquark model and try to analyze the possible origins for the spin transfer difference between them measured by the COMPASS collaboration. The intermediate heavier hyperon decay processes are considered, while the final hadron transverse momentum is also included. We find that after taking into account the asymmetric nucleon s/s¯ distribution effect, the results we get are qualitatively comparable with the difference of the COMPASS experimental data.

  16. Measurements of Direct Photon Double Longitudinal Spin Asymmetry at Large Rapidity

    NASA Astrophysics Data System (ADS)

    Bourgeois, Paul

    2008-10-01

    Direct photon production in polarized p-p collisions is expected to be the cleanest measurement of the gluon polarization. Current measurements using inclusive pion production, in the PHENIX central arms, suggest a small contribution from the gluons to the proton spin in the presently accessible Bjorken x range xBj>10-2. The addition of the Nose Cone Calorimeter (NCC) in the large rapidity 1<η<3 will allow PHENIX to access xBj˜10-3. In this talk I will present the prospects of measuring direct photon double longitudinal spin asymmetry ALL employing the NCC.

  17. Measurement of Single and Double Spin Asymmetries in Deep Inelastic Pion Electroproduction with a Longitudinally Polarized Target

    SciTech Connect

    Avakian, H; Bosted, P; Elouadrhiri, L; Adhikari, K P; Aghasyan, M; Amaryan, M; Anghinolfi, M; Baghdasaryan, H; Ball, J; Battaglieri, M; Bedlinskiy, I; Biselli, A S; Branford, D; Briscoe, W J; Brooks, W; Carman, D S; Casey, L; Cole, P L; Collins, P; Crabb, D; Crede, V; D'Angelo, A; Daniel, A; Dashyan, N; DeVita, R; DeSanctis, E; Deur, A; Dey, B; Dhamija, S; Dickson, R; Djalali, C; Dodge, G; Doughty, D; Dupre, R; El Alaoui, A; Eugenio, P; Fegan, S; Fersch, M; Guler, N; Guo, L; Hafidi, K; Hakobyan, H; Hanretty, C; Hassall, N; Heddle, D; Hicks, K; Holtrop, M; Ilieva, Y; Ireland, D G; Isupov, E L; Jawalkar, S S; Jo, H S; Joo, K; Keller, D; Khandaker, M; Khetarpal,; Kim, W; Klein, A; Klein, F J; Konczykowski, P; Kubarovsky, V; Kuhn, S E; Kuleshov, S V; Kuznetsov, V; Livingston, K; Lu, H Y; Markov, N; Mayer, M; McAndrew, J; McCracken, M E; McKInnon, B; Meyer, C A; Mineeva, T; Mirazita, M; Mokeev, V; Moreno, B; Moriya, K; Morrison, B; Moutarde, H; Munevar, E; Nadel-Turonski, P; Nasseripour, R; Niccolai, S; Niculescu, G; Niculescu, I; Niroula, M R; Osipenko, M; Ostrovidov, A I; Paremuzyan, R; Park, K; Park, S; Pasyuk, E; Anefalos Pereira, S; Perrin, Y; Pisano, S; Pogorelko, O; Price, J W; Procureur, S; Prok, Protopopescu; Raue, B A; Ricco, G; Ripani, M; Rosner, G; Rossi, P; Sabatie, F; Saini, M S; Salamanca, J; Salgado, C; Schumacher, R A; Seder, E; Seraydaryan, H; Sharabian, Y G; Sober, D I; Sokhan, D; Stapanyan, S S; Stepanyan, S; Stoler, P; Strauch, S; Suleiman, R; Taiuti, M; Tedeschi, D J; Tkachenko, S; Ungaro, M; Vernarsky, B; Vineyard, M F; Voutier, E; Watts, D P; Weinstein, L B; Weygand, D P; Wood, M H; Zhang, J; Zhao, B; Zhao, Z W

    2010-12-01

    We report the first measurement of the transverse momentum dependence of double spin asymmetries in semi-inclusive production of pions in deep inelastic scattering off the longitudinally polarized proton. Data have been obtained using a polarized electron beam of 5.7 GeV with the CLAS detector at the Thomas Jefferson National Accelerator Facility (JLab). A significant non-zero $\\sin2\\phi$ single spin asymmetry was also observed for the first time indicating strong spin-orbit correlations for transversely polarized quarks in the longitudinally polarized proton. The azimuthal modulations of single spin asymmetries have been measured over a wide kinematic range.

  18. Spin Structure Functions from Electron Scattering

    SciTech Connect

    Seonho Choi

    2012-09-01

    The spin structure of the nucleon can play a key testing ground for Quantum Chromo-Dynamics (QCD) at wide kinematic ranges from smaller to large four momentum transfer Q{sup 2}. The pioneering experiments have confirmed several QCD sum rules at high Q{sup 2} where a perturbative picture holds. For a full understanding of QCD at various scales, various measurements were made at intermediate and small Q{sup 2} region and their interpretation would be a challenging task due to the non-perturbative nature. Jefferson Lab has been one of the major experimental facilities for the spin structure with its polarized electron beams and various polarized targets. A few QCD sum rules have been compared with the measured spin structure functions g{sub 1}(x, Q{sup 2}) and g{sub 2}(x, Q{sup 2}) at low Q{sup 2} and surprising results have been obtained for the spin polarizabilities, {gamma}{sub 0} and {delta}{sub LT} . As for the proton spin structure functions, the lack of data for g{sub 2}(x,Q{sup 2}) structure functions has been complemented with a new experiment at Jefferson Lab, SANE. The results from SANE will provide a better picture of the proton spin structure at a wide kinematic range in x and Q{sup 2}.

  19. Longitudinal spin transfer to the {lambda} hyperon in semiinclusive deep-inelastic scattering

    SciTech Connect

    Airapetian, A.; Deconinck, W.; Lorenzon, W.; Akopov, N.; Akopov, Z.; Avakian, R.; Avetissian, A.; Elbakian, G.; Gharibyan, V.; Marukyan, H.; Rostomyan, A.; Taroian, S.; Amarian, M.; Andrus, A.; Bailey, P.; Bouwhuis, M.; Chiang, H. C.; Linden-Levy, L. A.; Makins, N. C. R.; Rubin, J.

    2006-10-01

    The transfer of polarization from a high-energy positron to a {lambda}{sup 0} hyperon produced in semiinclusive deep-inelastic scattering has been measured. The data have been obtained by the HERMES experiment at DESY using the 27.6 GeV longitudinally polarized positron beam of the HERA collider and unpolarized gas targets internal to the positron (electron) storage ring. The longitudinal spin-transfer coefficient is found to be D{sub LL{sup '}}{sup {lambda}}=0.11{+-}0.10(stat){+-}0.03(syst) at an average fractional energy carried by the {lambda}{sup 0} hyperon =0.45. The dependence of D{sub LL{sup '}}{sup {lambda}} on both the fractional energy z and the fractional longitudinal momentum x{sub F} is presented.

  20. Spin polarization in quantum point contact structures

    NASA Astrophysics Data System (ADS)

    Ngo, Anh; Ulloa, Sergio

    2008-03-01

    One of the important goals in the field of spintronics is to produce spin-polarized currents in semiconductors [1]. The Rashba spin-orbit interaction is useful in this regard, because its strength is controllable by applying an electric field. In this work we study ballistic transport through semiconductor quantum point contact systems under different confinement geometries and applied fields. In particular, we investigate how the lateral spin-orbit coupling, as induced by the lateral confinement potential, plays a non-trivial role on the spin polarization of the current, even in the absence of magnetic field. We find that high spin polarization can be obtained by controlling the asymmetric shape of the confinement potential, and contrast our results with previous work in the literature [2]. This behavior suggests a novel scheme to implement spin-filters without external magnetic fields, and we present its dependence on structural parameters. [1] S. A. Wolf, et al., Spintronics: a spin based electronic vision of the future, Science 294, 1488-1495 (2001). [2] M. Eto, et al., Spin polarization at semiconductor point contacts in absence of magnetic field, J. Phys. Soc. Jpn. 74, 1934 (2005).

  1. Investigation of the magnetic properties of insulating thin films using the longitudinal spin Seebeck effect

    SciTech Connect

    Kehlberger, A. Jakob, G.; Kläui, M.; Onbasli, M. C.; Kim, D. H.; Ross, C. A.

    2014-05-07

    The longitudinal spin Seebeck effect is used as a detector for the magnetic properties and switching characteristics of magnetic thin insulating films. We use a 300 nm and a 20 nm thick Yttrium Iron Garnet (YIG, Y{sub 3}Fe{sub 5}O{sub 12}) film prepared by pulsed laser deposition and afterwards coated by platinum for the detection of the thermally excited magnons by the inverse spin Hall effect. The inverse spin Hall signals reveal a magnetic uniaxial anisotropy along the direction of the platinum stripe in the thicker film. For the thin film we find a more isotropic behavior, which is complementarily observed using the magnetoresistance occurring at the platinum/YIG interface. We explain our results on the basis of x-ray diffraction data, which reveal a miscut of the substrate and film surface and an expansion of the YIG lattice. Both findings favor a growth-induced magnetic anisotropy that we observe.

  2. Precision measurement of the neutron spin dependent structure functions

    SciTech Connect

    Kolomensky, Y.G.

    1997-02-01

    In experiment E154 at the Stanford Linear Accelerator Center the spin dependent structure function g{sub 1}{sup n} (x, Q{sup 2}) of the neutron was measured by scattering longitudinally polarized 48.3 GeV electrons off a longitudinally polarized {sup 3}He target. The high beam energy allowed the author to extend the kinematic coverage compared to the previous SLAC experiments to 0.014 {le} x {le} 0.7 with an average Q{sup 2} of 5 GeV{sup 2}. The author reports the integral of the spin dependent structure function in the measured range to be {integral}{sub 0.014}{sup 0.7} dx g{sub 1}{sup n}(x, 5 GeV{sup 2}) = {minus}0.036 {+-} 0.004(stat.) {+-} 0.005(syst.). The author observes relatively large values of g{sub 1}{sup n} at low x that call into question the reliability of data extrapolation to x {r_arrow} 0. Such divergent behavior disagrees with predictions of the conventional Regge theory, but is qualitatively explained by perturbative QCD. The author performs a Next-to-Leading Order perturbative QCD analysis of the world data on the nucleon spin dependent structure functions g{sub 1}{sup p} and g{sub 1}{sup n} paying careful attention to the experimental and theoretical uncertainties. Using the parameterizations of the helicity-dependent parton distributions obtained in the analysis, the author evolves the data to Q{sup 2} = 5 GeV{sup 2}, determines the first moments of the polarized structure functions of the proton and neutron, and finds agreement with the Bjorken sum rule.

  3. Spin structure in high energy processes: Proceedings

    SciTech Connect

    DePorcel, L.; Dunwoodie, C.

    1994-12-01

    This report contains papers as the following topics: Spin, Mass, and Symmetry; physics with polarized Z{sup 0}s; spin and precision electroweak physics; polarized electron sources; polarization phenomena in quantum chromodynamics; polarized lepton-nucleon scattering; polarized targets in high energy physics; spin dynamics in storage rings and linear accelerators; spin formalism and applications to new physics searches; precision electroweak physics at LEP; recent results on heavy flavor physics from LEP experiments using 1990--1992 data; precise measurement of the left-right cross section asymmetry in Z boson production by electron-positron collisions; preliminary results on heavy flavor physics at SLD; QCD tests with SLD and polarized beams; recent results from TRISTAN at KEK; recent B physics results from CLEO; searching for the H dibaryon at Brookhaven; recent results from the compton observatory; the spin structure of the deuteron; spin structure of the neutron ({sup 3}HE) and the Bjoerken sum rule; a consumer`s guide to lattice QCD results; top ten models constrained by b {yields} sy; a review of the Fermilab fixed target program; results from the D0 experiment; results from CDF at FNAL; quantum-mechanical suppression of bremsstrahlung; report from the ZEUS collaboration at HERA; physics from the first year of H1 at HERA, and hard diffraction. These papers have been cataloged separately elsewhere.

  4. Spin-wave excitations induced by spin current in spin-valve structures

    NASA Astrophysics Data System (ADS)

    Liu, Haoliang; Sun, Dali; Zhang, Chuang; Groesbeck, Matthew; Vardeny, Zeev Valy; Department of Physics; Astronomy, University of Utah, Salt Lake City, Utah 84112, USA Team

    2016-03-01

    We have investigated the magnetization dynamics of NiFe/Pt/Co spin-valve structures with different Pt layer thickness, using a broadband ferromagnetic resonance (FMR) and Brillouin light scattering (BLS) at ambient temperature. We found that the Gilbert damping factor, α of the two ferromagnetic (FM) layer films in the spin-valve structure are significantly larger than α of each individual FM layer. We interpret the increase in α in the spin-valve configuration as due to an interaction between the FM layers mediated by the induced spin current through the Pt interlayer when FMR conditions are met for one of the FM. This was verified by BLS of the spin-valve structure, in which the magnons density in the adjacent FM layer is enhanced upon FMR of the other FM layer. We have studied this spin-current-mediated interaction as a function of the Pt interlayer. Work supported by the MURI-AFOSR Grant FA9550-14-1-0037, and the UofU facility center supported by NSF-MRSEC Grant DMR-1121252.

  5. THE SPIN STRUCTURE OF THE NUCLEON.

    SciTech Connect

    VOGELSANG, W.

    2005-05-23

    For many years now, spin has played a very prominent role in QCD. The field of QCD spin physics has been carried by the hugely successful experimental program of polarized deeply-inelastic lepton-nucleon scattering (DIS), and by a simultaneous tremendous progress in theory. A new milestone has now been reached with the advent of RHIC, the world's first polarized proton-proton collider. RHIC is poised to help answer many of the important question pertaining to the spin structure of the nucleon. Recently, it has also been proposed to study spin phenomena in transversely polarized {bar p}p collisions at the planned GSI-FAIR facility. This talk describes some of the opportunities provided by RHIC and the proposed GSI experiments.

  6. NMR longitudinal relaxation enhancement in metal halides by heteronuclear polarization exchange during magic-angle spinning

    NASA Astrophysics Data System (ADS)

    Shmyreva, Anna A.; Safdari, Majid; Furó, István; Dvinskikh, Sergey V.

    2016-06-01

    Orders of magnitude decrease of 207Pb and 199Hg NMR longitudinal relaxation times T1 upon magic-angle-spinning (MAS) are observed and systematically investigated in solid lead and mercury halides MeX2 (Me = Pb, Hg and X = Cl, Br, I). In lead(ii) halides, the most dramatic decrease of T1 relative to that in a static sample is in PbI2, while it is smaller but still significant in PbBr2, and not detectable in PbCl2. The effect is magnetic-field dependent but independent of the spinning speed in the range 200-15 000 Hz. The observed relaxation enhancement is explained by laboratory-frame heteronuclear polarization exchange due to crossing between energy levels of spin-1/2 metal nuclei and adjacent quadrupolar-spin halogen nuclei. The enhancement effect is also present in lead-containing organometal halide perovskites. Our results demonstrate that in affected samples, it is the relaxation data recorded under non-spinning conditions that characterize the local properties at the metal sites. A practical advantage of fast relaxation at slow MAS is that spectral shapes with orientational chemical shift anisotropy information well retained can be acquired within a shorter experimental time.

  7. NMR longitudinal relaxation enhancement in metal halides by heteronuclear polarization exchange during magic-angle spinning.

    PubMed

    Shmyreva, Anna A; Safdari, Majid; Furó, István; Dvinskikh, Sergey V

    2016-06-14

    Orders of magnitude decrease of (207)Pb and (199)Hg NMR longitudinal relaxation times T1 upon magic-angle-spinning (MAS) are observed and systematically investigated in solid lead and mercury halides MeX2 (Me = Pb, Hg and X = Cl, Br, I). In lead(ii) halides, the most dramatic decrease of T1 relative to that in a static sample is in PbI2, while it is smaller but still significant in PbBr2, and not detectable in PbCl2. The effect is magnetic-field dependent but independent of the spinning speed in the range 200-15 000 Hz. The observed relaxation enhancement is explained by laboratory-frame heteronuclear polarization exchange due to crossing between energy levels of spin-1/2 metal nuclei and adjacent quadrupolar-spin halogen nuclei. The enhancement effect is also present in lead-containing organometal halide perovskites. Our results demonstrate that in affected samples, it is the relaxation data recorded under non-spinning conditions that characterize the local properties at the metal sites. A practical advantage of fast relaxation at slow MAS is that spectral shapes with orientational chemical shift anisotropy information well retained can be acquired within a shorter experimental time. PMID:27306000

  8. New Results on Nucleon Spin Structure

    SciTech Connect

    Jian-Ping Chen

    2005-09-10

    Recent precision spin structure data from Jefferson Lab have significantly advanced our knowledge of nucleon structure in the valence quark (high-x) region and improved our understanding of higher-twist effects, spin sum rules and quark-hadron duality. First, results of a precision measurement of the neutron spin asymmetry, A{sub 1}{sup n}, in the high-x region are discussed. The new data shows clearly, for the first time, that A{sub 1}{sup n} becomes positive at high x. They provide crucial input for the global fits to world data to extract polarized parton distribution functions. Preliminary results on A{sub 1}{sup p} and A{sub 1}{sup d} in the high-x region have also become available. The up and down quark spin distributions in the nucleon were extracted. The results for {Delta}d/d disagree with the leading-order pQCD prediction assuming hadron helicity conservation. Then, results of a precision measurement of the g{sub 2}{sup n} structure function to study higher-twist effects are presented. The data show a clear deviation from the lead-twist contribution, indicating a significant higher-twist (twist-3 or higher) effect. The second moment of the spin structure functions and the twist-3 matrix element d{sub 2}{sup n} results were extracted at a high Q{sup 2} of 5 GeV{sup 2} from the measured A{sub 2}{sup n} in the high-x region in combination with existing world data and compared with a Lattice QCD calculation. Results for d{sub 2}{sup n} at low-to-intermediate Q{sup 2} from 0.1 to 0.9 GeV{sup 2} were also extracted from the JLab data. In the same Q{sup 2} range, the Q{sup 2} dependence of the moments of the nucleon spin structure functions was measured, providing a unique bridge linking the quark-gluon picture of the nucleon and the coherent hadronic picture. Sum rules and generalized forward spin polarizabilities were extracted and compared with Chiral Perturbation Theory calculations and phenomenological models. Finally, preliminary results on the resonance

  9. Measurement of inclusive spin structure functions of the deuteron

    NASA Astrophysics Data System (ADS)

    Yun, J.; Kuhn, S. E.; Dodge, G. E.; Forest, T. A.; Taiuti, M.; Adams, G. S.; Amaryan, M. J.; Anciant, E.; Anghinolfi, M.; Asavapibhop, B.; Asryan, G.; Audit, G.; Auger, T.; Avakian, H.; Barrow, S.; Battaglieri, M.; Beard, K.; Bektasoglu, M.; Bertozzi, W.; Bianchi, N.; Biselli, A. S.; Boiarinov, S.; Bosted, P.; Bouchigny, S.; Bradford, R.; Branford, D.; Brooks, W. K.; Bueltmann, S.; Burkert, V. D.; Butuceanu, C.; Calarco, J. R.; Carman, D. S.; Carnahan, B.; Cetina, C.; Ciciani, L.; Cole, P. L.; Coleman, A.; Connelly, J.; Cords, D.; Corvisiero, P.; Crabb, D.; Crannell, H.; Cummings, J.; Sanctis, E. De; Vita, R. De; Degtyarenko, P. V.; Demirchyan, R. A.; Denizli, H.; Dennis, L. C.; Dharmawardane, K. V.; Djalali, C.; Domingo, J.; Doughty, D.; Dragovitsch, P.; Dugger, M.; Dytman, S.; Eckhause, M.; Efremenko, Y. V.; Egiyan, H.; Egiyan, K. S.; Elouadrhiri, L.; Empl, A.; Farhi, L.; Fatemi, R.; Feuerbach, R. J.; Ficenec, J.; Fissum, K.; Freyberger, A.; Frolov, V.; Funsten, H.; Gaff, S. J.; Gai, M.; Gavalian, G.; Gavrilov, V. B.; Gilad, S.; Gilfoyle, G. P.; Giovanetti, K. L.; Girard, P.; Golovatch, E.; Gordon, C. I.; Griffioen, K. A.; Guidal, M.; Guillo, M.; Guo, L.; Gyurjyan, V.; Hadjidakis, C.; Hancock, D.; Hardie, J.; Heddle, D.; Heimberg, P.; Hersman, F. W.; Hicks, K.; Hicks, R. S.; Holtrop, M.; Hu, J.; Hyde-Wright, C. E.; Ito, M. M.; Jenkins, D.; Joo, K.; Keith, C.; Kelley, J. H.; Khandaker, M.; Kim, K. Y.; Kim, K.; Kim, W.; Klein, A.; Klein, F. J.; Klimenko, A. V.; Klusman, M.; Kossov, M.; Kramer, L. H.; Kuang, Y.; Kuhn, J.; Lachniet, J.; Laget, J. M.; Lawrence, D.; Leksin, G. A.; Loukachine, K.; Major, R. W.; Manak, J. J.; Marchand, C.; McAleer, S.; McNabb, J. W.; McCarthy, J.; Mecking, B. A.; Mestayer, M. D.; Meyer, C. A.; Minehart, R.; Mirazita, M.; Miskimen, R.; Mokeev, V.; Morrow, S.; Muccifora, V.; Mueller, J.; Murphy, L. Y.; Mutchler, G. S.; Napolitano, J.; Nelson, S. O.; Niccolai, S.; Niculescu, G.; Niczyporuk, B.; Niyazov, R. A.; Nozar, M.; O'Rielly, G. V.; Ohandjanyan, M. S.; Opper, A.; Ossipenko, M.; Park, K.; Patois, Y.; Peterson, G. A.; Philips, S.; Pivnyuk, N.; Pocanic, D.; Pogorelko, O.; Polli, E.; Preedom, B. M.; Price, J. W.; Protopopescu, D.; Qin, L. M.; Raue, B. A.; Riccardi, G.; Ricco, G.; Ripani, M.; Ritchie, B. G.; Rock, S.; Ronchetti, F.; Rossi, P.; Rowntree, D.; Rubin, P. D.; Sabourov, K.; Salgado, C. W.; Sapunenko, V.; Sargsyan, M.; Schumacher, R. A.; Serov, V. S.; Sharabian, Y. G.; Shaw, J.; Shuvalov, S. M.; Simionatto, S.; Skabelin, A.; Smith, E. S.; Smith, L. C.; Smith, T.; Sober, D. I.; Sorrell, L.; Spraker, M.; Stepanyan, S.; Stoler, P.; Taylor, S.; Tedeschi, D.; Thoma, U.; Thompson, R.; Todor, L.; Tung, T. Y.; Tur, C.; Vineyard, M. F.; Vlassov, A.; Wang, K.; Weinstein, L. B.; Weller, H.; Welsh, R.; Weygand, D. P.; Whisnant, S.; Witkowski, M.; Wolin, E.; Wood, M. H.; Yegneswaran, A.; Zhang, B.; Zhao, J.; Zhou, Z.

    2003-05-01

    We report the results of a new measurement of spin structure functions of the deuteron in the region of moderate momentum transfer [Q2=0.27 1.3 (GeV/c)2] and final hadronic state mass in the nucleon resonance region (W=1.08 2.0 GeV). We scattered a 2.5 GeV polarized continuous electron beam at Jefferson Lab off a dynamically polarized cryogenic solid state target (15ND3) and detected the scattered electrons with the CEBAF large acceptance spectrometer. From our data, we extract the longitudinal double spin asymmetry A|| and the spin structure function gd1. Our data are generally in reasonable agreement with existing data from SLAC where they overlap, and they represent a substantial improvement in statistical precision. We compare our results with expectations for resonance asymmetries and extrapolated deep inelastic scaling results. Finally, we evaluate the first moment of the structure function gd1 and study its approach to both the deep inelastic limit at large Q2 and to the Gerasimov-Drell-Hearn sum rule at the real photon limit (Q2→0). We find that the first moment varies rapidly in the Q2 range of our experiment and crosses zero at Q2 between 0.5 and 0.8 (GeV/c)2, indicating the importance of the Δ resonance at these momentum transfers.

  10. Nucleon Spin And Structure Studies With COMPASS

    SciTech Connect

    Platchkov, Stephane

    2006-07-11

    The COMPASS experiment at CERN investigates nucleon structure and spectroscopy with high-intensity muon and hadron beams. Between 2002 and 2004 COMPASS has mainly concentrated on the spin structure of the nucleon via deep-inelastic scattering of polarized muons on polarized nucleons. First results include measurements of the gluon contribution to the nucleon spin via charm production and high-pt pairs, {lambda} polarization, vector-meson production, Collins and Sivers asymmetries, inclusive and semi-inclusive deep-inelastic scattering asymmetries and a search for pentaquark states. A short overview of these results is presented.

  11. The Neutron and 3He Spin Structure Functions at Low Q^2

    SciTech Connect

    Vincent Sulkosky

    2009-08-01

    Experiment E97-110 was performed at the Thomas Jefferson National Accelerator Facility in Hall A to provide a precise measurement of the moments of the neutron and $^{3}$He spin structure functions. A longitudinally-polarized electron beam was scattered from a longitudinally or transversely polarized $^{3}$He target. The extended Gerasimov-Drell-Hearn integral and other moments of the neutron and $^{3}$He spin structure functions were extracted at very low momentum transfers (0.02 $< Q^{2} <$ 0.3 [GeV$/c$]$^{2}$). These data allow us to make a benchmark check of Chiral Perturbation Theory calculations in a region where they are expected to be valid. In these proceedings, the experimental details are discussed and preliminary results on the moments of the spin structure functions are presented.

  12. Perturbative harmonic modulation of longitudinal electron-spin magnetization for short T1 determination

    NASA Astrophysics Data System (ADS)

    Suzuki, Takayuki

    2015-10-01

    Longitudinally detected T1 measurement scheme (LOD-T1) is studied in detail. In contrast to the original work on LOD-T1, using high power microwave pulses, this work deals with general and practically frequent cases in which perfect inversion of the electron-spin magnetization is not feasible due to the effect of relaxation during microwave pulses. Theoretical studies, numerical simulations, and experiments reveal a pair of separate contributions of the dynamics of the longitudinal magnetization to the LOD signal, namely, the periodic modulation and the relaxation contributions. The latter alone which is of interest can be extracted to give relaxation curves. In addition, it is shown that T1 information can be obtained even when the available microwave power is so low that the electron magnetization can only be perturbatively modulated, at the cost of reduced sensitivity. To overcome this, a modified pulse sequence is proposed. In this new method, the pulse excitations are repeated during half a period of the resonance of the longitudinal detection circuit. The method is called the perturbative harmonic modulation method for longitudinally detected T1 measurement (HM-LOD-T1). HM-LOD-T1 experiments are demonstrated in 2,2-diphenyl-1-picrylhydrazyl (DPPH).

  13. Cooling overall spin temperature: Protein NMR experiments optimized for longitudinal relaxation effects

    NASA Astrophysics Data System (ADS)

    Deschamps, Michaël; Campbell, Iain D.

    2006-02-01

    In experiments performed on protonated proteins at high fields, 80% of the NMR spectrometer time is spent waiting for the 1H atoms to recover their polarization after recording the free induction decay. Selective excitation of a fraction of the protons in a large molecule has previously been shown to lead to faster longitudinal relaxation for the selected protons [K. Pervushin, B. Vögeli, A. Eletsky, Longitudinal 1H relaxation optimization in TROSY NMR spectroscopy, J. Am. Chem. Soc. 124 (2002) 12898-12902; P. Schanda, B. Brutscher, Very fast two-dimensional NMR spectroscopy for real-time investigation of dynamic events in proteins on the time scale of seconds, J. Am. Chem. Soc. 127 (2005) 8014-8015; H.S. Attreya, T. Szyperski, G-matrix Fourier transform NMR spectroscopy for complete protein resonance assignment, Proc. Natl. Acad. Sci. USA 101 (2004) 9642-9647]. The pool of non-selected protons acts as a "thermal bath" and spin-diffusion processes ("flip-flop" transitions) channel the excess energy from the excited pool to the non-selected protons in regions of the molecule where other relaxation processes can dissipate the excess energy. We present here a sensitivity enhanced HSQC sequence (COST-HSQC), based on one selective E-BURP pulse, which can be used on protonated 15N enriched proteins (with or without 13C isotopic enrichment). This experiment is compared to a gradient sensitivity enhanced HSQC with a water flip-back pulse (the water flip-back pulse quenches the spin diffusion between 1H N and 1H α spins). This experiment is shown to have significant advantages in some circumstances. Some observed limitations, namely sample overheating with short recovery delays and complex longitudinal relaxation behaviour are discussed and analysed.

  14. Cooling overall spin temperature: protein NMR experiments optimized for longitudinal relaxation effects.

    PubMed

    Deschamps, Michaël; Campbell, Iain D

    2006-02-01

    In experiments performed on protonated proteins at high fields, 80% of the NMR spectrometer time is spent waiting for the (1)H atoms to recover their polarization after recording the free induction decay. Selective excitation of a fraction of the protons in a large molecule has previously been shown to lead to faster longitudinal relaxation for the selected protons [K. Pervushin, B. Vögeli, A. Eletsky, Longitudinal (1)H relaxation optimization in TROSY NMR spectroscopy, J. Am. Chem. Soc. 124 (2002) 12898-12902; P. Schanda, B. Brutscher, Very fast two-dimensional NMR spectroscopy for real-time investigation of dynamic events in proteins on the time scale of seconds, J. Am. Chem. Soc. 127 (2005) 8014-8015; H.S. Attreya, T. Szyperski, G-matrix Fourier transform NMR spectroscopy for complete protein resonance assignment, Proc. Natl. Acad. Sci. USA 101 (2004) 9642-9647]. The pool of non-selected protons acts as a "thermal bath" and spin-diffusion processes ("flip-flop" transitions) channel the excess energy from the excited pool to the non-selected protons in regions of the molecule where other relaxation processes can dissipate the excess energy. We present here a sensitivity enhanced HSQC sequence (COST-HSQC), based on one selective E-BURP pulse, which can be used on protonated (15)N enriched proteins (with or without (13)C isotopic enrichment). This experiment is compared to a gradient sensitivity enhanced HSQC with a water flip-back pulse (the water flip-back pulse quenches the spin diffusion between (1)H(N) and (1)H(alpha) spins). This experiment is shown to have significant advantages in some circumstances. Some observed limitations, namely sample overheating with short recovery delays and complex longitudinal relaxation behaviour are discussed and analysed. PMID:16249110

  15. High-spin structure of 102Ru

    NASA Astrophysics Data System (ADS)

    Sohler, D.; Timár, J.; Rainovski, G.; Joshi, P.; Starosta, K.; Fossan, D. B.; Molnár, J.; Wadsworth, R.; Algora, A.; Bednarczyk, P.; Curien, D.; Dombrádi, Zs.; Duchene, G.; Gizon, A.; Gizon, J.; Jenkins, D. G.; Koike, T.; Krasznahorkay, A.; Paul, E. S.; Raddon, P. M.; Scheurer, J. N.; Simons, A. J.; Vaman, C.; Wilkinson, A. R.; Zolnai, L.

    2005-06-01

    High-spin states in the nucleus 102Ru have been investigated via the 96Zr(13C,α3n) reaction at beam energies of 51 and 58 MeV, using the euroball IV γ-ray spectrometer and the diamant charged particle array. Several new high-spin bands have been established. The ground-state band has been extended up to Ex~12 MeV with Iπ=(26+); the previously published negative-parity bands have been extended up to Ex~11 and ˜ 9 MeV with Iπ=(23-) and (20-), respectively. The deduced high-spin structure has been compared with Woods-Saxon total Routhian surface calculations and, on the basis of the measured Routhians, aligned angular momenta, and B(M1)/B(E2) ratios, νh11/2(g7/2,d5/2) configurations are suggested for the negative-parity structures.

  16. Finite-temperature spin dynamics near the quantum critical point of transverse field Ising chain with a small longitudinal field

    NASA Astrophysics Data System (ADS)

    Kormos, Márton; Wu, Jianda; Si, Qimiao

    2014-03-01

    When the transverse-field Ising chain at its quantum critical point is subjected to a small longitudinal field, the perturbed conformal field theory led to a field theory with an exotic E8 symmetry. Recent neutron scattering experiments have provided evidence for the lightest two particles in this E8 model in the quasi-1D Ising ferromagnet CoNb2O6. While the zero temperature dynamic of the model is well known, its finite-temperature counterpart has not yet been systematically studied. We study the low-frequency dynamical spin structure factor at finite temperatures using the form-factor method. We show that the dominant contribution to the spin dynamics comes from the channel between two lightest particles, and demonstrate how the spin dynamics differ from a diffusion form. Using these results, we determine the temperature dependence of the NMR relaxation rate. We suggest that, for CoNb2O6, measurements of the NMR relaxation rate provide a means to further test the applicability of the E8 model.

  17. Competing spin pumping effects in magnetic hybrid structures

    NASA Astrophysics Data System (ADS)

    Azevedo, A.; Alves Santos, O.; Fonseca Guerra, G. A.; Cunha, R. O.; Rodríguez-Suárez, R.; Rezende, S. M.

    2014-02-01

    Pure spin current can be detected by its conversion into charge current in nanometer thick nonmagnetic metal layer with large spin-orbit coupling by means of the inverse spin Hall effect (ISHE). Recently, it has been shown that the metallic ferromagnet Permalloy (Py) can also be used as spin current detector in experiments in which an ISHE voltage is created in a Py layer in contact with the insulating ferromagnet yttrium iron garnet (YIG) under a thermal gradient in the longitudinal spin Seebeck configuration. Here, we report experiments with microwave driven spin pumping in heterostructures made with single crystal YIG film and a nanometer thick Py or Pt layer that show that Py behaves differently than nonmagnetic metals as a spin current detector. The results are attributed to the competition between the spin currents generated by the dynamics of the magnetizations in YIG and in Py, which are exchange coupled at the interface.

  18. Flexible heat-flow sensing sheets based on the longitudinal spin Seebeck effect using one-dimensional spin-current conducting films

    PubMed Central

    Kirihara, Akihiro; Kondo, Koichi; Ishida, Masahiko; Ihara, Kazuki; Iwasaki, Yuma; Someya, Hiroko; Matsuba, Asuka; Uchida, Ken-ichi; Saitoh, Eiji; Yamamoto, Naoharu; Kohmoto, Shigeru; Murakami, Tomoo

    2016-01-01

    Heat-flow sensing is expected to be an important technological component of smart thermal management in the future. Conventionally, the thermoelectric (TE) conversion technique, which is based on the Seebeck effect, has been used to measure a heat flow by converting the flow into electric voltage. However, for ubiquitous heat-flow visualization, thin and flexible sensors with extremely low thermal resistance are highly desired. Recently, another type of TE effect, the longitudinal spin Seebeck effect (LSSE), has aroused great interest because the LSSE potentially offers favourable features for TE applications such as simple thin-film device structures. Here we demonstrate an LSSE-based flexible TE sheet that is especially suitable for a heat-flow sensing application. This TE sheet contained a Ni0.2Zn0.3Fe2.5O4 film which was formed on a flexible plastic sheet using a spray-coating method known as “ferrite plating”. The experimental results suggest that the ferrite-plated film, which has a columnar crystal structure aligned perpendicular to the film plane, functions as a unique one-dimensional spin-current conductor suitable for bendable LSSE-based sensors. This newly developed thin TE sheet may be attached to differently shaped heat sources without obstructing an innate heat flux, paving the way to versatile heat-flow measurements and management. PMID:26975208

  19. Flexible heat-flow sensing sheets based on the longitudinal spin Seebeck effect using one-dimensional spin-current conducting films

    NASA Astrophysics Data System (ADS)

    Kirihara, Akihiro; Kondo, Koichi; Ishida, Masahiko; Ihara, Kazuki; Iwasaki, Yuma; Someya, Hiroko; Matsuba, Asuka; Uchida, Ken-Ichi; Saitoh, Eiji; Yamamoto, Naoharu; Kohmoto, Shigeru; Murakami, Tomoo

    2016-03-01

    Heat-flow sensing is expected to be an important technological component of smart thermal management in the future. Conventionally, the thermoelectric (TE) conversion technique, which is based on the Seebeck effect, has been used to measure a heat flow by converting the flow into electric voltage. However, for ubiquitous heat-flow visualization, thin and flexible sensors with extremely low thermal resistance are highly desired. Recently, another type of TE effect, the longitudinal spin Seebeck effect (LSSE), has aroused great interest because the LSSE potentially offers favourable features for TE applications such as simple thin-film device structures. Here we demonstrate an LSSE-based flexible TE sheet that is especially suitable for a heat-flow sensing application. This TE sheet contained a Ni0.2Zn0.3Fe2.5O4 film which was formed on a flexible plastic sheet using a spray-coating method known as “ferrite plating”. The experimental results suggest that the ferrite-plated film, which has a columnar crystal structure aligned perpendicular to the film plane, functions as a unique one-dimensional spin-current conductor suitable for bendable LSSE-based sensors. This newly developed thin TE sheet may be attached to differently shaped heat sources without obstructing an innate heat flux, paving the way to versatile heat-flow measurements and management.

  20. Flexible heat-flow sensing sheets based on the longitudinal spin Seebeck effect using one-dimensional spin-current conducting films.

    PubMed

    Kirihara, Akihiro; Kondo, Koichi; Ishida, Masahiko; Ihara, Kazuki; Iwasaki, Yuma; Someya, Hiroko; Matsuba, Asuka; Uchida, Ken-ichi; Saitoh, Eiji; Yamamoto, Naoharu; Kohmoto, Shigeru; Murakami, Tomoo

    2016-01-01

    Heat-flow sensing is expected to be an important technological component of smart thermal management in the future. Conventionally, the thermoelectric (TE) conversion technique, which is based on the Seebeck effect, has been used to measure a heat flow by converting the flow into electric voltage. However, for ubiquitous heat-flow visualization, thin and flexible sensors with extremely low thermal resistance are highly desired. Recently, another type of TE effect, the longitudinal spin Seebeck effect (LSSE), has aroused great interest because the LSSE potentially offers favourable features for TE applications such as simple thin-film device structures. Here we demonstrate an LSSE-based flexible TE sheet that is especially suitable for a heat-flow sensing application. This TE sheet contained a Ni0.2Zn0.3Fe2.5O4 film which was formed on a flexible plastic sheet using a spray-coating method known as "ferrite plating". The experimental results suggest that the ferrite-plated film, which has a columnar crystal structure aligned perpendicular to the film plane, functions as a unique one-dimensional spin-current conductor suitable for bendable LSSE-based sensors. This newly developed thin TE sheet may be attached to differently shaped heat sources without obstructing an innate heat flux, paving the way to versatile heat-flow measurements and management. PMID:26975208

  1. Temperature dependent spin structures in Hexaferrite crystal

    NASA Astrophysics Data System (ADS)

    Chao, Y. C.; Lin, J. G.; Chun, S. H.; Kim, K. H.

    2016-01-01

    In this work, the Hexaferrite Ba0.5Sr1.5Zn2Fe12O22 (BSZFO) is studied due to its interesting characteristics of long-wavelength spin structure. Ferromagnetic resonance (FMR) is used to probe the magnetic states of BSZFO single crystal and its temperature dependence behavior is analyzed by decomposing the multiple lines of FMR spectra into various phases. Distinguished phase transition is observed at 110 K for one line, which is assigned to the ferro(ferri)-magnetic transition from non-collinear to collinear spin state.

  2. Spin Hall Effect in Doped Semiconductor Structures

    NASA Astrophysics Data System (ADS)

    Tse, Wang-Kong; Das Sarma, S.

    2006-02-01

    In this Letter we present a microscopic theory of the extrinsic spin Hall effect based on the diagrammatic perturbation theory. Side-jump and skew-scattering contributions are explicitly taken into account to calculate the spin Hall conductivity, and we show that their effects scale as σxySJ/σxySS˜(ℏ/τ)/ɛF, with τ being the transport relaxation time. Motivated by recent experimental work we apply our theory to n- and p-doped 3D and 2D GaAs structures, obtaining σs/σc˜10-3-10-4, where σs(c) is the spin Hall (charge) conductivity, which is in reasonable agreement with the recent experimental results of Kato et al. [Science 306, 1910 (2004)]SCIEAS0036-807510.1126/science.1105514 in n-doped 3D GaAs system.

  3. Longitudinal structure of ballooning MHD disturbances in a model magnetosphere

    NASA Astrophysics Data System (ADS)

    Mazur, N. G.; Fedorov, E. N.; Pilipenko, V. A.

    2014-05-01

    Large-scale toroidal Pc5 pulsations are commonly treated as Alfven oscillations of a magnetic field line. According to observations, their longitudinal structure is described well by theory. At the same time, the longitudinal structure of azimuthal small-scale poloidal Pc5 pulsations is virtually unknown. These pulsations are associated with ballooning disturbances described by a system of coupled equations for Alfvenic and slow magnetosonic (SMS) modes. In this work, the Voigt model is used to describe the equilibrium finite-pressure plasma configuration in an inhomogeneous magnetosphere plasma in a curved magnetic field. Spectral characteristics and the spatial structure of natural ballooning modes are calculated for this model. The model calculations demonstrate the possibility of different longitudinal scales for transverse and longitudinal magnetic components of oscillations near the top of the field line.

  4. The extraction of the spin structure function, g2 (and g1) at low Bjorken x

    SciTech Connect

    Ndukum, Luwani Z.

    2015-08-01

    The Spin Asymmetries of the Nucleon Experiment (SANE) used the Continuous Electron Beam Accelerator Facility at Jefferson Laboratory in Newport News, VA to investigate the spin structure of the proton. The experiment measured inclusive double polarization electron asymmetries using a polarized electron beam, scattered off a solid polarized ammonia target with target polarization aligned longitudinal and near transverse to the electron beam, allowing the extraction of the spin asymmetries A1 and A2, and spin structure functions g1 and g2. Polarized electrons of energies of 4.7 and 5.9 GeV were used. The scattered electrons were detected by a novel, non-magnetic array of detectors observing a four-momentum transfer range of 2.5 to 6.5 GeV*V. This document addresses the extraction of the spin asymmetries and spin structure functions, with a focus on spin structure function, g2 (and g1) at low Bjorken x. The spin structure functions were measured as a function of x and W in four Q square bins. A full understanding of the low x region is necessary to get clean results for SANE and extend our understanding of the kinematic region at low x.

  5. Measurement of parity-violating spin asymmetries in W± production at midrapidity in longitudinally polarized p +p collisions

    NASA Astrophysics Data System (ADS)

    Adare, A.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Akimoto, R.; Alexander, J.; Alfred, M.; Aoki, K.; Apadula, N.; Aramaki, Y.; Asano, H.; Aschenauer, E. C.; Atomssa, E. T.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Bai, X.; Bandara, N. S.; Bannier, B.; Barish, K. N.; Bassalleck, B.; Bathe, S.; Baublis, V.; Baumann, C.; Baumgart, S.; Bazilevsky, A.; Beaumier, M.; Beckman, S.; Belmont, R.; Berdnikov, A.; Berdnikov, Y.; Black, D.; Blau, D. S.; Bok, J. S.; Boyle, K.; Brooks, M. L.; Bryslawskyj, J.; Buesching, H.; Bumazhnov, V.; Butsyk, S.; Campbell, S.; Chen, C.-H.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choi, J. B.; Choi, S.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cole, B. A.; Connors, M.; Cronin, N.; Crossette, N.; Csanád, M.; Csörgő, T.; Dairaku, S.; Danley, T. W.; Datta, A.; Daugherity, M. S.; David, G.; Deblasio, K.; Dehmelt, K.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dietzsch, O.; Ding, L.; Dion, A.; Diss, P. B.; Do, J. H.; Donadelli, M.; D'Orazio, L.; Drapier, O.; Drees, A.; Drees, K. A.; Durham, J. M.; Durum, A.; Edwards, S.; Efremenko, Y. V.; Engelmore, T.; Enokizono, A.; En'yo, H.; Esumi, S.; Eyser, K. O.; Fadem, B.; Feege, N.; Fields, D. E.; Finger, M.; Finger, M.; Fleuret, F.; Fokin, S. L.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fukao, Y.; Fusayasu, T.; Gainey, K.; Gal, C.; Gallus, P.; Garg, P.; Garishvili, A.; Garishvili, I.; Ge, H.; Giordano, F.; Glenn, A.; Gong, X.; Gonin, M.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gu, Y.; Gunji, T.; Guragain, H.; Hachiya, T.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamilton, H. F.; Han, S. Y.; Hanks, J.; Hasegawa, S.; Haseler, T. O. S.; Hashimoto, K.; Hayano, R.; Hayashi, S.; He, X.; Hemmick, T. K.; Hester, T.; Hill, J. C.; Hollis, R. S.; Homma, K.; Hong, B.; Horaguchi, T.; Hoshino, T.; Hotvedt, N.; Huang, J.; Huang, S.; Ichihara, T.; Iinuma, H.; Ikeda, Y.; Imai, K.; Imazu, Y.; Imrek, J.; Inaba, M.; Iordanova, A.; Isenhower, D.; Isinhue, A.; Ivanishchev, D.; Jacak, B. V.; Javani, M.; Jeon, S. J.; Jezghani, M.; Jia, J.; Jiang, X.; Johnson, B. M.; Joo, E.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kamin, J.; Kanda, S.; Kang, B. H.; Kang, J. H.; Kang, J. S.; Kapustinsky, J.; Karatsu, K.; Kawall, D.; Kazantsev, A. V.; Kempel, T.; Key, J. A.; Khachatryan, V.; Khandai, P. K.; Khanzadeev, A.; Kihara, K.; Kijima, K. M.; Kim, B. I.; Kim, C.; Kim, D. H.; Kim, D. J.; Kim, E.-J.; Kim, G. W.; Kim, H.-J.; Kim, M.; Kim, Y.-J.; Kim, Y. K.; Kimelman, B.; Kinney, E.; Kistenev, E.; Kitamura, R.; Klatsky, J.; Kleinjan, D.; Kline, P.; Koblesky, T.; Kofarago, M.; Komkov, B.; Koster, J.; Kotchetkov, D.; Kotov, D.; Krizek, F.; Kurita, K.; Kurosawa, M.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Lee, D. M.; Lee, G. H.; Lee, J.; Lee, K. B.; Lee, K. S.; Lee, S.; Lee, S. H.; Lee, S. R.; Leitch, M. J.; Leite, M. A. L.; Leitgab, M.; Lewis, B.; Li, X.; Lim, S. H.; Linden Levy, L. A.; Liu, M. X.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Makek, M.; Manion, A.; Manko, V. I.; Mannel, E.; Maruyama, T.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; McKinney, C.; Meles, A.; Mendoza, M.; Meredith, B.; Miake, Y.; Mibe, T.; Midori, J.; Mignerey, A. C.; Miller, A. J.; Milov, A.; Mishra, D. K.; Mitchell, J. T.; Miyasaka, S.; Mizuno, S.; Mohanty, A. K.; Mohapatra, S.; Montuenga, P.; Moon, H. J.; Moon, T.; Morrison, D. P.; Moskowitz, M.; Moukhanova, T. V.; Murakami, T.; Murata, J.; Mwai, A.; Nagae, T.; Nagamiya, S.; Nagashima, K.; Nagle, J. L.; Nagy, M. I.; Nakagawa, I.; Nakagomi, H.; Nakamiya, Y.; Nakamura, K. R.; Nakamura, T.; Nakano, K.; Nattrass, C.; Netrakanti, P. K.; Nihashi, M.; Niida, T.; Nishimura, S.; Nouicer, R.; Novák, T.; Novitzky, N.; Nukariya, A.; Nyanin, A. S.; Obayashi, H.; O'Brien, E.; Ogilvie, C. A.; Oide, H.; Okada, K.; Orjuela Koop, J. D.; Osborn, J. D.; Oskarsson, A.; Ozaki, H.; Ozawa, K.; Pak, R.; Pantuev, V.; Papavassiliou, V.; Park, I. H.; Park, J. S.; Park, S.; Park, S. K.; Pate, S. F.; Patel, L.; Patel, M.; Pei, H.; Peng, J.-C.; Perepelitsa, D. V.; Perera, G. D. N.; Peressounko, D. Yu.; Perry, J.; Petti, R.; Pinkenburg, C.; Pinson, R.; Pisani, R. P.; Purschke, M. L.; Qu, H.; Rak, J.; Ramson, B. J.; Ravinovich, I.; Read, K. F.; Reynolds, D.; Riabov, V.; Riabov, Y.; Richardson, E.; Rinn, T.; Riveli, N.; Roach, D.; Roche, G.; Rolnick, S. D.; Rosati, M.; Rowan, Z.; Rubin, J. G.; Ryu, M. S.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sako, H.; Samsonov, V.; Sarsour, M.; Sato, S.; Sawada, S.; Schaefer, B.; Schmoll, B. K.; Sedgwick, K.; Seele, J.; Seidl, R.; Sekiguchi, Y.; Sen, A.; Seto, R.; Sett, P.; Sexton, A.; Sharma, D.; Shaver, A.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Skolnik, M.; Slunečka, M.; Snowball, M.; Solano, S.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Stankus, P. W.; Steinberg, P.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Stone, M. R.; Sugitate, T.; Sukhanov, A.; Sumita, T.; Sun, J.; Sziklai, J.; Takagui, E. M.; Takahara, A.; Taketani, A.; Tanaka, Y.; Taneja, S.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tennant, E.; Tieulent, R.; Timilsina, A.; Todoroki, T.; Tomášek, M.; Torii, H.; Towell, C. L.; Towell, M.; Towell, R.; Towell, R. S.; Tserruya, I.; Tsuchimoto, Y.; Vale, C.; van Hecke, H. W.; Vargyas, M.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Virius, M.; Voas, B.; Vrba, V.; Vznuzdaev, E.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Watanabe, Y. S.; Wei, F.; Whitaker, S.; White, A. S.; White, S. N.; Winter, D.; Wolin, S.; Woody, C. L.; Wysocki, M.; Xia, B.; Xue, L.; Yalcin, S.; Yamaguchi, Y. L.; Yanovich, A.; Ying, J.; Yokkaichi, S.; Yoo, J. H.; Yoon, I.; You, Z.; Younus, I.; Yu, H.; Yushmanov, I. E.; Zajc, W. A.; Zelenski, A.; Zhou, S.; Zou, L.; Phenix Collaboration

    2016-03-01

    We present midrapidity measurements from the PHENIX experiment of large parity-violating single-spin asymmetries of high transverse momentum electrons and positrons from W±/Z decays, produced in longitudinally polarized p +p collisions at center of mass energies of √{s }=500 and 510 GeV. These asymmetries allow direct access to the antiquark polarized parton distribution functions due to the parity-violating nature of the W -boson coupling to quarks and antiquarks. The results presented are based on data collected in 2011, 2012, and 2013 with an integrated luminosity of 240 pb-1 , which exceeds previous PHENIX published results by a factor of more than 27. These high Q2 data probe the parton structure of the proton at W mass scale and provide an important addition to our understanding of the antiquark parton helicity distribution functions at an intermediate Bjorken x value of roughly MW/√{s }=0.16 .

  6. On Dynamics of Spinning Structures

    NASA Technical Reports Server (NTRS)

    Gupta, K. K.; Ibrahim, A.

    2012-01-01

    This paper provides details of developments pertaining to vibration analysis of gyroscopic systems, that involves a finite element structural discretization followed by the solution of the resulting matrix eigenvalue problem by a progressive, accelerated simultaneous iteration technique. Thus Coriolis, centrifugal and geometrical stiffness matrices are derived for shell and line elements, followed by the eigensolution details as well as solution of representative problems that demonstrates the efficacy of the currently developed numerical procedures and tools.

  7. Structurally Dynamic Spin Market Networks

    NASA Astrophysics Data System (ADS)

    Horváth, Denis; Kuscsik, Zoltán

    The agent-based model of stock price dynamics on a directed evolving complex network is suggested and studied by direct simulation. The stationary regime is maintained as a result of the balance between the extremal dynamics, adaptivity of strategic variables and reconnection rules. The inherent structure of node agent "brain" is modeled by a recursive neural network with local and global inputs and feedback connections. For specific parametric combination the complex network displays small-world phenomenon combined with scale-free behavior. The identification of a local leader (network hub, agent whose strategies are frequently adapted by its neighbors) is carried out by repeated random walk process through network. The simulations show empirically relevant dynamics of price returns and volatility clustering. The additional emerging aspects of stylized market statistics are Zipfian distributions of fitness.

  8. Origin of longitudinal spin excitations in iron-pnictide parent compounds

    NASA Astrophysics Data System (ADS)

    Fidrysiak, Maciej

    2016-02-01

    We investigate longitudinal spin excitations (LSEs) as a probe of microscopic origin of magnetic ordering in parent pnictides BaFe2As2 and NaFeAs. Currently adopted interpretation of LSEs as bottom of particle-hole continuum points unambiguously toward itinerant-electron magnetism, but is difficult to reconcile with available optical measurements. We study the possibility that the LSEs originate from multi-magnon processes which are not energetically constrained by optical spectroscopy and do not sharply distinguish between local-moment and itinerant scenarios. Two mechanisms, capable of enhancing multi-magnon continuum to the level indicated by neutron scattering experiments, are proposed. The first emphasizes itinerant electrons and is based on electronic transitions between magnetically split bands, while the other relies on purely spin fluctuations close to a magnetic quantum phase transition. Electronic excitations enhance multi-magnon contribution to LSEs for small Fermi surface taking part in the SDW instability, but are insufficient to account for measured intensities. The correct order of LSEs, on the other hand, can be reproduced by the spin fluctuation mechanism for a reasonable set of parameters.

  9. Observation of longitudinal spin-Seebeck effect in cobalt-ferrite epitaxial thin films

    SciTech Connect

    Niizeki, Tomohiko; Kikkawa, Takashi; Uchida, Ken-ichi; Oka, Mineto; Suzuki, Kazuya Z.; Yanagihara, Hideto; Kita, Eiji; Saitoh, Eiji

    2015-05-15

    The longitudinal spin-Seebeck effect (LSSE) has been investigated in cobalt ferrite (CFO), an exceptionally hard magnetic spinel ferrite. A bilayer of a polycrystalline Pt and an epitaxially-strained CFO(110) exhibiting an in-plane uniaxial anisotropy was prepared by reactive rf sputtering technique. Thermally generated spin voltage in the CFO layer was measured via the inverse spin-Hall effect in the Pt layer. External-magnetic-field (H) dependence of the LSSE voltage (V{sub LSSE}) in the Pt/CFO(110) sample with H ∥ [001] was found to exhibit a hysteresis loop with a high squareness ratio and high coercivity, while that with H∥[11{sup -}0] shows a nearly closed loop, reflecting the different anisotropies induced by the epitaxial strain. The magnitude of V{sub LSSE} has a linear relationship with the temperature difference (ΔT), giving the relatively large V{sub LSSE} /ΔT of about 3 μV/K for CFO(110) which was kept even at zero external field.

  10. Measurement of single- and double-spin asymmetries in deep inelastic pion electroproduction with a longitudinally polarized target.

    PubMed

    Avakian, H; Bosted, P; Burkert, V D; Elouadrhiri, L; Adhikari, K P; Aghasyan, M; Amaryan, M; Anghinolfi, M; Baghdasaryan, H; Ball, J; Battaglieri, M; Bedlinskiy, I; Biselli, A S; Branford, D; Briscoe, W J; Brooks, W; Carman, D S; Casey, L; Cole, P L; Collins, P; Crabb, D; Crede, V; D'Angelo, A; Daniel, A; Dashyan, N; De Vita, R; De Sanctis, E; Deur, A; Dey, B; Dhamija, S; Dickson, R; Djalali, C; Dodge, G; Doughty, D; Dupre, R; El Alaoui, A; Eugenio, P; Fegan, S; Fersch, R; Forest, T A; Fradi, A; Gabrielyan, M Y; Gavalian, G; Gevorgyan, N; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Gohn, W; Gothe, R W; Griffioen, K A; Guidal, M; Guler, N; Guo, L; Hafidi, K; Hakobyan, H; Hanretty, C; Hassall, N; Heddle, D; Hicks, K; Holtrop, M; Ilieva, Y; Ireland, D G; Isupov, E L; Jawalkar, S S; Jo, H S; Joo, K; Keller, D; Khandaker, M; Khetarpal, P; Kim, W; Klein, A; Klein, F J; Konczykowski, P; Kubarovsky, V; Kuhn, S E; Kuleshov, S V; Kuznetsov, V; Livingston, K; Lu, H Y; Markov, N; Mayer, M; Martinez, D; McAndrew, J; McCracken, M E; McKinnon, B; Meyer, C A; Mineeva, T; Mirazita, M; Mokeev, V; Moreno, B; Moriya, K; Morrison, B; Moutarde, H; Munevar, E; Nadel-Turonski, P; Nasseripour, R; Niccolai, S; Niculescu, G; Niculescu, I; Niroula, M R; Osipenko, M; Ostrovidov, A I; Paremuzyan, R; Park, K; Park, S; Pasyuk, E; Pereira, S Anefalos; Perrin, Y; Pisano, S; Pogorelko, O; Price, J W; Procureur, S; Prok, Y; Protopopescu, D; Raue, B A; Ricco, G; Ripani, M; Rosner, G; Rossi, P; Sabatié, F; Saini, M S; Salamanca, J; Salgado, C; Schumacher, R A; Seder, E; Seraydaryan, H; Sharabian, Y G; Sober, D I; Sokhan, D; Stepanyan, S S; Stepanyan, S; Stoler, P; Strauch, S; Suleiman, R; Taiuti, M; Tedeschi, D J; Tkachenko, S; Ungaro, M; Vernarsky, B; Vineyard, M F; Voutier, E; Watts, D P; Weinstein, L B; Weygand, D P; Wood, M H; Zhang, J; Zhao, B; Zhao, Z W

    2010-12-31

    We report the first measurement of the transverse momentum dependence of double-spin asymmetries in semi-inclusive production of pions in deep-inelastic scattering off the longitudinally polarized proton. Data have been obtained using a polarized electron beam of 5.7 GeV with the CLAS detector at the Jefferson Lab (JLab). Modulations of single spin asymmetries over the azimuthal angle between lepton scattering and hadron production planes ϕ have been measured over a wide kinematic range in Bjorken x and virtual photon squared four-momentum Q2. A significant nonzero sin2ϕ single spin asymmetry was observed for the first time indicating strong spin-orbit correlations for transversely polarized quarks in the longitudinally polarized proton. PMID:21231647

  11. Measurement of Single- and Double-Spin Asymmetries in Deep Inelastic Pion Electroproduction with a Longitudinally Polarized Target

    SciTech Connect

    Avakian, H.; Bosted, P.; Burkert, V. D.; Elouadrhiri, L.; Brooks, W.; Carman, D. S.; Deur, A.; Guo, L.; Kubarovsky, V.; Nadel-Turonski, P.; Weygand, D. P.; Adhikari, K. P.; Amaryan, M.; Dodge, G.; Gavalian, G.; Guler, N.; Klein, A.; Kuhn, S. E.; Niroula, M. R.; Seraydaryan, H.

    2010-12-31

    We report the first measurement of the transverse momentum dependence of double-spin asymmetries in semi-inclusive production of pions in deep-inelastic scattering off the longitudinally polarized proton. Data have been obtained using a polarized electron beam of 5.7 GeV with the CLAS detector at the Jefferson Lab (JLab). Modulations of single spin asymmetries over the azimuthal angle between lepton scattering and hadron production planes {phi} have been measured over a wide kinematic range in Bjorken x and virtual photon squared four-momentum Q{sup 2}. A significant nonzero sin2{phi} single spin asymmetry was observed for the first time indicating strong spin-orbit correlations for transversely polarized quarks in the longitudinally polarized proton.

  12. Spin waves in triple-q structures: Application to USb

    SciTech Connect

    Jensen, J.; Bak, P.

    1981-06-01

    The spin-wave spectrum in a system with triple-q magnetic structure is calculated. The spin waves differ distinctly from those in the corresponding single-q structure, but agree with the excitations observed by Lander and Stirling in uranium antimonide (USb). Their experiments thus directly verify that the spins in USb are ordered in the triple-q structure.

  13. Proton Spin Structure in the Resonance Region

    SciTech Connect

    F. R. Wesselmann; K. Slifer; S. Tajima; A. Aghalaryan; A. Ahmidouch; R. Asaturyan; F. Bloch; W. Boeglin; P. Bosted; C. Carasco; R. Carlini; J. Cha; J. P. Chen; M. E. Christy; L. Cole; L. Coman; D. Crabb; S. Danagoulian; D. Day; J. Dunne; M. Elaasar; R. Ent; H. Fenker; E. Frlez; L. Gan; D. Gaskell; J. Gomez; B. Hu; M. K. Jones; J. Jourdan; C. Keith; C. E. Keppel; M. Khandaker; A. Klein; L. Kramer; Y. Liang; J. Lichtenstadt; R. Lindgren; D. Mack; P. McKee; D. McNulty; D. Meekins; H. Mkrtchyan; R. Nasseripour; I. Niculescu; K. Normand; B. Norum; D. Pocanic; Y. Prok; B. Raue; J. Reinhold; J. Roche; D. Rohe; O. A. Rondon; N. Savvinov; B. Sawatzky; M. Seely; I. Sick; C. Smith; G. Smith; S. Stepanyan; L. Tang; G. Testa; W. Vulcan; K. Wang; G. Warren; S. Wood; C. Yan; L. Yuan; Junho Yun; Markus Zeier; Hong Guo Zhu

    2006-10-11

    The RSS collaboration has measured the spin structure functions g{sub 1} and g{sub 2} of the proton at Jefferson Lab using the lab's polarized electron beam, the Hall C HMS spectrometer and the UVa polarized solid target. The asymmetries A{sub parallel} and A{sub perp} were measured at the elastic peak and in the region of the nucleon resonances (1.085 GeV < W < 1.910 GeV) at an average four momentum transfer of Q{sup 2} = 1.3 GeV{sup 2}. The extracted spin structure functions and their kinematic dependence make a significant contribution in the study of higher-twist effects and polarized duality tests.

  14. High-spin structure of 104Pd

    NASA Astrophysics Data System (ADS)

    Sohler, D.; Kuti, I.; Timár, J.; Joshi, P.; Molnár, J.; Paul, E. S.; Starosta, K.; Wadsworth, R.; Algora, A.; Bednarczyk, P.; Curien, D.; Dombrádi, Zs.; Duchene, G.; Fossan, D. B.; Gál, J.; Gizon, A.; Gizon, J.; Jenkins, D. G.; Juhász, K.; Kalinka, G.; Koike, T.; Krasznahorkay, A.; Nyakó, B. M.; Raddon, P. M.; Rainovski, G.; Scheurer, J. N.; Simons, A. J.; Vaman, C.; Wilkinson, A. R.; Zolnai, L.

    2012-04-01

    The high-spin structure of the nucleus 104Pd was studied through the 96Zr(13C,5n) reaction at incident energies of 51 and 58 MeV, using the Euroball IV γ-ray spectrometer in conjunction with the DIAMANT charged-particle array. Several new medium- and high-spin bands were revealed. The already known positive-parity yrast and the negative-parity cascades were extended up to Ex˜13, ˜11, and ˜9 MeV with Iπ=(26+), Iπ=(23-), and (20-), respectively. The deduced band structures were compared with Woods-Saxon total Routhian surface (TRS) calculations. In addition, non-yrast low-lying positive-parity bands were identified, which were assigned to soft γ-vibrational excitations.

  15. Spin Transport in Nondegenerate Si with a Spin MOSFET Structure at Room Temperature

    NASA Astrophysics Data System (ADS)

    Sasaki, Tomoyuki; Ando, Yuichiro; Kameno, Makoto; Tahara, Takayuki; Koike, Hayato; Oikawa, Tohru; Suzuki, Toshio; Shiraishi, Masashi

    2014-09-01

    Spin transport in nondegenerate semiconductors is expected to pave the way to the creation of spin transistors, spin logic devices, and reconfigurable logic circuits, because room-temperature (RT) spin transport in Si has already been achieved. However, RT spin transport has been limited to degenerate Si, which makes it difficult to produce spin-based signals because a gate electric field cannot be used to manipulate such signals. Here, we report the experimental demonstration of spin transport in nondegenerate Si with a spin metal-oxide-semiconductor field-effect transistor (MOSFET) structure. We successfully observe the modulation of the Hanle-type spin-precession signals, which is a characteristic spin dynamics in nondegenerate semiconductors. We obtain long spin transport of more than 20 μm and spin rotation greater than 4π at RT. We also observe gate-induced modulation of spin-transport signals at RT. The modulation of the spin diffusion length as a function of a gate voltage is successfully observed, which we attribute to the Elliott-Yafet spin relaxation mechanism. These achievements are expected to lead to the creation of practical Si-based spin MOSFETs.

  16. Structure of the Nucleon Spin on the Light Cone

    SciTech Connect

    Pasquini, B.

    2008-10-13

    The spin structure of the nucleon is studied in a light-cone description of the nucleon where the Fock expansion is truncated to consider only valence quarks. Transverse momentum dependent parton distributions and transverse-spin densities, defined through the generalized parton distributions in the impact parameter space, are investigated as new tools to reveal the spin-spin and spin-orbit correlations for different quark and nucleon polarizations.

  17. Longitudinal structure of solar activity: Regular and stochastic behavior

    NASA Astrophysics Data System (ADS)

    Erofeev, D. V.

    2015-12-01

    The ratio of regular and stochastic components in the behavior of the longitudinal-temporal distribution of solar activity is studied with the use of correlation and spectral analysis of data on sunspot groups for 12 solar cycles. It was found that data samples of about 10 years in length often (in 50% of cases) show the presence of regular structures in the longitudinal distribution of sunspot groups. However, these structures are nonstationary; their characteristic scales and rotation periods vary when changing from one 10-year interval to another. The behavior of the longitudinal structure of sunspot activity is mainly stochastic on a long time scale (50-100 years); it is characterized by a wide spectrum of spatial scales and a continuous spectrum of rotation periods, which takes a period from 25.6 to 28.5 days.

  18. Longitudinal Double Spin Asymmetry in Inclusive Jet Production atSTAR

    SciTech Connect

    Kowalik, Katarzyna; STAR Collaboration

    2006-08-15

    This contribution reports on the first measurement of the longitudinal double-spin asymmetry A{sub LL} for the inclusive production of jets in polarized proton-proton collisions at {radical}s = 200 GeV. The data were collected with STAR at RHIC in the years 2003 and 2004, and correspond to a sampled integrated luminosity of 0.3 pb{sup -1} with beam polarizations up to 45%. The results on A{sub LL} cover jet transverse momenta 5 < p{sub T} < 17 GeV/c and agree with perturbative QCD evaluations based on deep-inelastic scattering parametrizations for the gluon polarization in the proton. The results disfavor large positive gluon polarization in the polarized proton.

  19. Longitudinal double spin asymmetries in single hadron quasi-real photoproduction at high pT

    NASA Astrophysics Data System (ADS)

    Adolph, C.; Akhunzyanov, R.; Alexeev, M. G.; Alexeev, G. D.; Amoroso, A.; Andrieux, V.; Anosov, V.; Augustyniak, W.; Austregesilo, A.; Azevedo, C. D. R.; Badełek, 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.; Büchele, M.; Burtin, E.; 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.; Dünnweber, W.; Dziewiecki, M.; Efremov, A.; Eversheim, P. D.; Eyrich, W.; Faessler, M.; Ferrero, A.; Finger, M.; Finger, M.; Fischer, H.; Franco, C.; du Fresne von Hohenesche, N.; Friedrich, J. M.; Frolov, V.; Fuchey, E.; Gautheron, F.; Gavrichtchouk, O. P.; Gerassimov, S.; Giordano, F.; Gnesi, I.; Gorzellik, M.; Grabmüller, S.; Grasso, A.; Grosse Perdekamp, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; Hahne, D.; von Harrach, D.; Hashimoto, R.; Heinsius, F. H.; 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.; Jörg, 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.; Königsmann, K.; Konorov, I.; Konstantinov, V. F.; Kotzinian, A. M.; Kouznetsov, O.; Krämer, M.; Kremser, P.; Krinner, F.; Kroumchtein, Z. V.; Kuchinski, N.; Kuhn, R.; 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.; Matoušek, J.; Matsuda, H.; Matsuda, T.; Meshcheryakov, G.; Meyer, W.; Michigami, T.; Mikhailov, Yu. V.; Miyachi, Y.; Montuenga, P.; Nagaytsev, A.; Nerling, F.; Neyret, D.; Nikolaenko, V. I.; Nový, 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.; Pešek, M.; Peshekhonov, D. V.; Platchkov, S.; Pochodzalla, J.; Polyakov, V. A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Riedl, C.; Rossiyskaya, N. S.; Ryabchikov, D. I.; Rychter, A.; Samoylenko, V. D.; Sandacz, A.; Santos, C.; Sarkar, S.; Savin, I. A.; Sbrizzai, G.; Schiavon, P.; Schmidt, K.; Schmieden, H.; Schönning, K.; Schopferer, S.; Selyunin, A.; Shevchenko, O. Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Sozzi, F.; Srnka, A.; Stolarski, M.; Sulc, M.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Tosello, F.; Tskhay, V.; Uhl, S.; Veloso, J.; Virius, M.; Weisrock, T.; Wilfert, M.; ter Wolbeek, J.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.

    2016-02-01

    We measured the longitudinal double spin asymmetries ALL for single hadron muoproduction off protons and deuterons at photon virtuality Q2 < 1(GeV / c) 2 for transverse hadron momenta pT in the range 1 GeV / c to 4 GeV / c. They were determined using COMPASS data taken with a polarised muon beam of 160 GeV / c or 200 GeV / c impinging on polarised 6LiD or NH3 targets. The experimental asymmetries are compared to next-to-leading order pQCD calculations, and are sensitive to the gluon polarisation ΔG inside the nucleon in the range of the nucleon momentum fraction carried by gluons 0.05

  20. High-spin structure in 40K

    NASA Astrophysics Data System (ADS)

    Söderström, P.-A.; Recchia, F.; Nyberg, J.; Gadea, A.; Lenzi, S. M.; Poves, A.; Ataç, A.; Aydin, S.; Bazzacco, D.; Bednarczyk, P.; Bellato, M.; Birkenbach, B.; Bortolato, D.; Boston, A. J.; Boston, H. C.; Bruyneel, B.; Bucurescu, D.; Calore, E.; Cederwall, B.; Charles, L.; Chavas, J.; Colosimo, S.; Crespi, F. C. L.; Cullen, D. M.; de Angelis, G.; Désesquelles, P.; Dosme, N.; Duchêne, G.; Eberth, J.; Farnea, E.; Filmer, F.; Görgen, A.; Gottardo, A.; Grębosz, J.; Gulmini, M.; Hess, H.; Hughes, T. A.; Jaworski, G.; Jolie, J.; Joshi, P.; Judson, D. S.; Jungclaus, A.; Karkour, N.; Karolak, M.; Kempley, R. S.; Khaplanov, A.; Korten, W.; Ljungvall, J.; Lunardi, S.; Maj, A.; Maron, G.; Męczyński, W.; Menegazzo, R.; Mengoni, D.; Michelagnoli, C.; Molini, P.; Napoli, D. R.; Nolan, P. J.; Norman, M.; Obertelli, A.; Podolyak, Zs.; Pullia, A.; Quintana, B.; Redon, N.; Regan, P. H.; Reiter, P.; Robinson, A. P.; Şahin, E.; Simpson, J.; Salsac, M. D.; Smith, J. F.; Stézowski, O.; Theisen, Ch.; Tonev, D.; Unsworth, C.; Ur, C. A.; Valiente-Dobón, J. J.; Wiens, A.

    2012-11-01

    High-spin states of 40K have been populated in the fusion-evaporation reaction 12C(30Si,np)40K and studied by means of γ-ray spectroscopy techniques using one triple-cluster detector of the Advanced Gamma Tracking Array at the Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro. Several states with excitation energy up to 8 MeV and spin up to 10- have been discovered. These states are discussed in terms of J=3 and T=0 neutron-proton hole pairs. Shell-model calculations in a large model space have shown good agreement with the experimental data for most of the energy levels. The evolution of the structure of this nucleus is here studied as a function of excitation energy and angular momentum.

  1. High-spin structure of 134Xe

    NASA Astrophysics Data System (ADS)

    Vogt, A.; Birkenbach, B.; Reiter, P.; Blazhev, A.; Siciliano, M.; Valiente-Dobón, J. J.; Wheldon, C.; Bazzacco, D.; Bowry, M.; Bracco, A.; Bruyneel, B.; Chakrawarthy, R. S.; Chapman, R.; Cline, D.; Corradi, L.; Crespi, F. C. L.; Cromaz, M.; de Angelis, G.; Eberth, J.; Fallon, P.; Farnea, E.; Fioretto, E.; Freeman, S. J.; Gadea, A.; Geibel, K.; Gelletly, W.; Gengelbach, A.; Giaz, A.; Görgen, A.; Gottardo, A.; Hayes, A. B.; Hess, H.; Hua, H.; John, P. R.; Jolie, J.; Jungclaus, A.; Korten, W.; Lee, I. Y.; Leoni, S.; Liang, X.; Lunardi, S.; Macchiavelli, A. O.; Menegazzo, R.; Mengoni, D.; Michelagnoli, C.; Mijatović, T.; Montagnoli, G.; Montanari, D.; Napoli, D.; Pearson, C. J.; Pellegri, L.; Podolyák, Zs.; Pollarolo, G.; Pullia, A.; Radeck, F.; Recchia, F.; Regan, P. H.; Şahin, E.; Scarlassara, F.; Sletten, G.; Smith, J. F.; Söderström, P.-A.; Stefanini, A. M.; Steinbach, T.; Stezowski, O.; Szilner, S.; Szpak, B.; Teng, R.; Ur, C.; Vandone, V.; Ward, D.; Warner, D. D.; Wiens, A.; Wu, C. Y.

    2016-05-01

    Detailed spectroscopic information on the N ˜82 nuclei is necessary to benchmark shell-model calculations in the region. The nuclear structure above long-lived isomers in 134Xe is investigated after multinucleon transfer (MNT) and actinide fission. Xenon-134 was populated as (i) a transfer product in 238U+ 136Xe and 208Pb+ 136Xe MNT reactions and (ii) as a fission product in the 238U+ 136Xe reaction employing the high-resolution Advanced Gamma Tracking Array (AGATA). Trajectory reconstruction has been applied for the complete identification of beamlike transfer products with the magnetic spectrometer PRISMA. The 198Pt 136Xe MNT reaction was studied with the γ -ray spectrometer GAMMASPHERE in combination with the gas detector array Compact Heavy Ion Counter (CHICO). Several high-spin states in 134Xe on top of the two long-lived isomers are discovered based on γ γ -coincidence relationships and information on the γ -ray angular distributions as well as excitation energies from the total kinetic energy loss and fission fragments. The revised level scheme of 134Xe is extended up to an excitation energy of 5.832 MeV with tentative spin-parity assignments up to 16+. Previous assignments of states above the 7- isomer are revised. Latest shell-model calculations employing two different effective interactions reproduce the experimental findings and support the new spin and parity assignments.

  2. A Bayesian Approach for Analyzing Longitudinal Structural Equation Models

    ERIC Educational Resources Information Center

    Song, Xin-Yuan; Lu, Zhao-Hua; Hser, Yih-Ing; Lee, Sik-Yum

    2011-01-01

    This article considers a Bayesian approach for analyzing a longitudinal 2-level nonlinear structural equation model with covariates, and mixed continuous and ordered categorical variables. The first-level model is formulated for measures taken at each time point nested within individuals for investigating their characteristics that are dynamically…

  3. Spin wave resonance detection using magnetic tunnel junction structure

    NASA Astrophysics Data System (ADS)

    Bi, Chong; Fan, Xin; Pan, Liqing; Kou, Xiaoming; Wu, Jun; Yang, Qinghui; Zhang, Huaiwu; Xiao, John Q.

    2011-11-01

    We have demonstrated that spin wave resonance in a permalloy microstrip can be detected by an electrical method based on magnetic tunnel junction structures. The detection method promises high spatial resolution and sensitivity. Both even and odd spin wave resonance modes can be clearly observed in a permalloy microstrip. The spin wave induced voltage is proportional to the input microwave power at each resonance mode. Data analysis using the model of quantized dipole-exchange spin wave resonance suggests the edge pinning of spin wave sensitively depends on the order of the spin wave mode, as well as on the excitation frequency for modes of the higher order.

  4. Extracting W Single Spin Asymmetry in Longitudinally Polarized pp Collisions at PHENIX forward arms

    NASA Astrophysics Data System (ADS)

    Meles, Abraham

    2014-09-01

    The parity-violating longitudinal single spin asymmetry AL in the production of W bosons in p + p collisions at √{ s} = 510 GeV is sensitive to the polarization of light quarks and anti-quarks in the proton. However, identifying the muons from the decay of the W is challenging due to a great background of hadronic processes and other muon producing processes. In the forward and backward hemispheres of PHENIX at RHIC, the muon spectrometers have been recently upgraded in order to provide additional trigger and tracking information to suppress those backgrounds. One of those upgrades is the Forward Vertex (FVTX) detector, a silicon-strip tracker. In 2013, PHENIX collected approximately 240 pb-1 of polarized p + p collisions at √{ s} = 510 GeV with a beam polarization of 56 %. The ability of the FVTX to improve the W signal will be reviewed, over view of the analysis techniques used to extract the signal from the data in RHIC 2013 run will be discussed. The parity-violating longitudinal single spin asymmetry AL in the production of W bosons in p + p collisions at √{ s} = 510 GeV is sensitive to the polarization of light quarks and anti-quarks in the proton. However, identifying the muons from the decay of the W is challenging due to a great background of hadronic processes and other muon producing processes. In the forward and backward hemispheres of PHENIX at RHIC, the muon spectrometers have been recently upgraded in order to provide additional trigger and tracking information to suppress those backgrounds. One of those upgrades is the Forward Vertex (FVTX) detector, a silicon-strip tracker. In 2013, PHENIX collected approximately 240 pb-1 of polarized p + p collisions at √{ s} = 510 GeV with a beam polarization of 56 %. The ability of the FVTX to improve the W signal will be reviewed, over view of the analysis techniques used to extract the signal from the data in RHIC 2013 run will be discussed. Support from US Department of Energy.

  5. Temperature dependences of magnetic anisotropy and longitudinal spin Seebeck effect in Y3Fe5O12

    NASA Astrophysics Data System (ADS)

    Kalappattil, Vijaysankar; Das, Raja; Phan, Manh-Huong; Srikanth, Hariharan

    Spin caloritronics is an emerging, exciting research area in condensed matter owing to its potential use in advanced spintronics devices. Pure spin current without having charge current has been achieved though spin Seebeck effect (SSE). Over the last 7 years SSE has been observed in ferromagnetic metals, insulators, and semiconductors using longitudinal and transverse SSE measurement configurations. In this work, we have carried out an experimental study to understand the effect of magnetic anisotropy on the temperature evolution of longitudinal spin Seebeck effect (LSSE) in a single crystalline yttrium iron garnet (YIG). The effective anisotropy field (HK) and inverse spin Hall (ISH) voltage (VISH) were measured using the radio-frequency transverse susceptibility (TS) and LSSE configuration, respectively. The VISH of a 15 nm Pt strip on (6*2*1 mm) YIG slab with a temperature gradient of 3 K was measured in the temperature range of 120 to 300 K. The observed values of VISH vary from 1 microV for 120 K to 0.5 microV for 300 K, These values fall into the previously reported theoretical and experimental results. The temperature evolution of HKhas been compared with that of VISH to gain better fundamental understanding. Work is supported by ARO through Grant No. W911NF-15-1-0626.

  6. How to reveal metastable skyrmionic spin structures by spin-polarized scanning tunneling microscopy

    NASA Astrophysics Data System (ADS)

    Dupé, B.; Kruse, C. N.; Dornheim, T.; Heinze, S.

    2016-05-01

    We predict the occurrence of metastable skyrmionic spin structures such as antiskyrmions and higher-order skyrmions in ultra-thin transition-metal films at surfaces using Monte Carlo simulations based on a spin Hamiltonian parametrized from density functional theory calculations. We show that such spin structures will appear with a similar contrast in spin-polarized scanning tunneling microscopy images. Both skyrmions and antiskyrmions display a circular shape for out-of-plane magnetized tips and a two-lobe butterfly contrast for in-plane tips. An unambiguous distinction can be achieved by rotating the tip magnetization direction without requiring the information of all components of the magnetization.

  7. Separated spin-up and spin-down evolution of degenerated electrons in two-dimensional systems: Dispersion of longitudinal collective excitations in plane and nanotube geometry

    NASA Astrophysics Data System (ADS)

    Andreev, Pavel A.; Kuz'menkov, L. S.

    2016-01-01

    Applying the separated spin evolution quantum hydrodynamics to the two-dimensional electron gas in plane samples and nanotubes located in external magnetic fields we have found a novel type of waves in the electron gas which is called spin-electron acoustic wave. A separate spin-up and spin-down electrons' evolution reveals the replacement of the Langmuir wave by a pair of hybrid waves. One of the two hybrid waves is a modified Langmuir wave. Another hybrid wave is a spin-electron acoustic wave. We studied the dispersion of these waves in two-dimensional structures of electrons. We also considered the dependence of dispersion properties on spin polarization of electrons in an external magnetic field.

  8. Studying the Nucleon Structure with Spin

    SciTech Connect

    Hasell, D. K.

    2007-10-26

    The BLAST (Bates Large Acceptance Spectrometer Toroid) collaboration is finalizing the analysis of a systematic study of the spin-dependent, electromagnetic interaction on hydrogen and deuterium. The experiment utilized: the highly polarized electron beam of the MIT-Bates Linear Accelerator Center stored in the South Hall Ring; an internal gas target of isotopically pure and highly polarized hydrogen or deuterium provided by an atomic beam source; and the symmetric, general purpose BLAST spectrometer. By making simultaneous measurements of many reaction channels for different combinations of beam helicity and target polarization BLAST is providing new, precise measurements for the nucleon and deuteron elastic form factors as well as studying the structure of deuterium and pion production from hydrogen and deuterium. A brief overview of the experiment will be presented together with a selection results.

  9. Spin Structure of the Nucleon - Proceedings of the Riken Symposium

    NASA Astrophysics Data System (ADS)

    Shibata, S.; Ohta, N.; Saito, T.-A.

    1996-08-01

    The Table of Contents for the full book PDF is as follows: * Organizing Committee * Foreword * Theoretical Overview * The Context of High Energy QCD Spin Physics * Experimental Studies I * PHENIX and Spin Physics * RHIC Spin Project - Acceleration of Polarized Protons * CIAE Activities for the PHENIX Experiment * Spin Physics with PHENIX Detector System at RHIC * Experiments on Spin-dependent Structure Functions of the Nucleon * Measurements of the Spin-dependent Structure Function of the Nucleon at the Spin Muon Collaboration * Theoretical Studies * Higher-twist Effects in Spin Structure Functions * Light Hadrons from Lattice QCD in a (2.4 fm)3 Box at 4-GeV Cutoff * Tensor Charge of the Nucleon on the Lattice * Perturbative QCD Study on the Chiral-Odd Twist-3 Structure Function: hL(x,Q2) * Strange Matrix Elements of the Proton and Instantons in QCD * Experimental Studies II * Proton Structure Functions from ZEUS * Measurements of the Photon Structure Functions F_{2}^γ * Constraint on the Proton Structure from CDF: Lepton Charge Asymmetry in W Decays * A Search for Jet Handedness in Hadronic Z0 Decays * Concluding Remarks * High Energy Spin Physics - Past, Present and Future * Program

  10. Structural Damage Detection Using Slopes of Longitudinal Vibration Shapes

    DOE PAGESBeta

    Xu, W.; Zhu, W. D.; Smith, S. A.; Cao, M. S.

    2016-03-18

    While structural damage detection based on flexural vibration shapes, such as mode shapes and steady-state response shapes under harmonic excitation, has been well developed, little attention is paid to that based on longitudinal vibration shapes that also contain damage information. This study originally formulates a slope vibration shape for damage detection in bars using longitudinal vibration shapes. To enhance noise robustness of the method, a slope vibration shape is transformed to a multiscale slope vibration shape in a multiscale domain using wavelet transform, which has explicit physical implication, high damage sensitivity, and noise robustness. These advantages are demonstrated in numericalmore » cases of damaged bars, and results show that multiscale slope vibration shapes can be used for identifying and locating damage in a noisy environment. A three-dimensional (3D) scanning laser vibrometer is used to measure the longitudinal steady-state response shape of an aluminum bar with damage due to reduced cross-sectional dimensions under harmonic excitation, and results show that the method can successfully identify and locate the damage. Slopes of longitudinal vibration shapes are shown to be suitable for damage detection in bars and have potential for applications in noisy environments.« less

  11. Complete Suppression of Longitudinal Spin Seebeck Effect by Frozen Magnetization Dynamics in Y3Fe5O12

    NASA Astrophysics Data System (ADS)

    Kikkawa, Takashi; Uchida, Ken-ichi; Daimon, Shunsuke; Saitoh, Eiji

    2016-06-01

    The spin Seebeck effect (SSE) in a Pt-film/Y3Fe5O12 (YIG)-slab junction system has been investigated at low temperatures and under various magnetic fields in the longitudinal configuration. We found that, by increasing applied magnetic fields, the SSE signal gradually decreases and converges to zero without showing sign reversal. The complete field-induced suppression of the SSE is interpreted in terms of the effect of the Zeeman gap in magnon excitation.

  12. Longitudinal relaxation in dipole-coupled homonuclear three-spin systems: Distinct correlations and odd spectral densities

    NASA Astrophysics Data System (ADS)

    Chang, Zhiwei; Halle, Bertil

    2015-12-01

    A system of three dipole-coupled spins exhibits a surprisingly intricate relaxation behavior. Following Hubbard's pioneering 1958 study, many authors have investigated different aspects of this problem. Nevertheless, on revisiting this classic relaxation problem, we obtain several new results, some of which are at variance with conventional wisdom. Most notably from a fundamental point of view, we find that the odd-valued spectral density function influences longitudinal relaxation. We also show that the effective longitudinal relaxation rate for a non-isochronous three-spin system can exhibit an unusual inverted dispersion step. To clarify these and other issues, we present a comprehensive theoretical treatment of longitudinal relaxation in a three-spin system of arbitrary geometry and with arbitrary rotational dynamics. By using the Liouville-space formulation of Bloch-Wangsness-Redfield theory and a basis of irreducible spherical tensor operators, we show that the number of relaxation components in the different cases can be deduced from symmetry arguments. For the isochronous case, we present the relaxation matrix in analytical form, whereas, for the non-isochronous case, we employ a computationally efficient approach based on the stochastic Liouville equation.

  13. Longitudinal relaxation in dipole-coupled homonuclear three-spin systems: Distinct correlations and odd spectral densities

    SciTech Connect

    Chang, Zhiwei; Halle, Bertil

    2015-12-21

    A system of three dipole-coupled spins exhibits a surprisingly intricate relaxation behavior. Following Hubbard’s pioneering 1958 study, many authors have investigated different aspects of this problem. Nevertheless, on revisiting this classic relaxation problem, we obtain several new results, some of which are at variance with conventional wisdom. Most notably from a fundamental point of view, we find that the odd-valued spectral density function influences longitudinal relaxation. We also show that the effective longitudinal relaxation rate for a non-isochronous three-spin system can exhibit an unusual inverted dispersion step. To clarify these and other issues, we present a comprehensive theoretical treatment of longitudinal relaxation in a three-spin system of arbitrary geometry and with arbitrary rotational dynamics. By using the Liouville-space formulation of Bloch-Wangsness-Redfield theory and a basis of irreducible spherical tensor operators, we show that the number of relaxation components in the different cases can be deduced from symmetry arguments. For the isochronous case, we present the relaxation matrix in analytical form, whereas, for the non-isochronous case, we employ a computationally efficient approach based on the stochastic Liouville equation.

  14. Spin-torsion effects in the hyperfine structure of methanol

    SciTech Connect

    Coudert, L. H. Gutlé, C.; Huet, T. R.; Grabow, J.-U.; Levshakov, S. A.

    2015-07-28

    The magnetic hyperfine structure of the non-rigid methanol molecule is investigated experimentally and theoretically. 12 hyperfine patterns are recorded using molecular beam microwave spectrometers. These patterns, along with previously recorded ones, are analyzed in an attempt to evidence the effects of the magnetic spin-torsion coupling due to the large amplitude internal rotation of the methyl group [J. E. M. Heuvel and A. Dymanus, J. Mol. Spectrosc. 47, 363 (1973)]. The theoretical approach setup to analyze the observed data accounts for this spin-torsion in addition to the familiar magnetic spin-rotation and spin-spin interactions. The theoretical approach relies on symmetry considerations to build a hyperfine coupling Hamiltonian and spin-rotation-torsion wavefunctions compatible with the Pauli exclusion principle. Although all experimental hyperfine patterns are not fully resolved, the line position analysis yields values for several parameters including one describing the spin-torsion coupling.

  15. Spinor helicity structures in higher spin theories

    NASA Astrophysics Data System (ADS)

    Ananth, Sudarshan

    2012-11-01

    It is shown that the coefficient of the cubic interaction vertex, in higher spin Lagrangians, has a very simple form when written in terms of spinor helicity products. The result for a higher-spin field, of spin λ, is equal to the corresponding Yang-Mills coefficient raised to the power λ. Among other things, this suggests perturbative ties, similar to the KLT relations, between higher spin theories and pure Yang-Mills. This result is obtained in four-dimensional flat spacetime.

  16. Spin Structure with JLab 6 and 12 GeV

    SciTech Connect

    Jian-Ping Chen

    2012-02-01

    Highlights of JLab 6 GeV results on spin structure study and plan for 12 GeV program. Spin structure study is full of surprises and puzzles. A decade of experiments from JLab yield these exciting results: (1) valence spin structure; (2) precision measurements of g{sub 2}/d{sub 2} - high-twist; (3) spin sum rules and polarizabilities; and (4) first neutron transversity. There is a bright future as the 12 GeV Upgrade will greatly enhance our capability: (1) Precision determination of the valence quark spin structure flavor separation; (2) Precision measurements of g{sub 2}/d{sub 2}; and (3) Precision extraction of transversity/tensor charge.

  17. Exploring the transverse spin structure of the nucleon

    SciTech Connect

    D'Alesio, Umberto

    2008-10-13

    We discuss our present understanding of the transverse spin structure of the nucleon and of related properties originating from parton transverse motion. Starting from the transversity distribution and the ways to access it, we then address the role played by spin and transverse momentum dependent (TMD) distributions in azimuthal and transverse single spin asymmetries. The latest extractions of the Sivers, Collins and transversity functions are also presented.

  18. The Spin Structure of the nucleon

    NASA Astrophysics Data System (ADS)

    Deur, Alexandre

    2015-10-01

    This talk will review the status of the experiments studying the spin structure of the nucleon. After a brief overview of the topics, I will focus on the program measuring the generalized Gerasimov-Drell-Hearn (GDH) sum, in the context of connecting the effective descriptions of the strong force at long distances to its fundamental partonic description at short distances. The generalized GDH sum rule is a theoretical relation valid at any distance. Consequently, it can be an Ariadne's thread to follow to understand how the transition between the partonic to hadronic descriptions happens. Measurements at intermediate and short distances have been made available in the 1990s and 2000s. Long distance results are being now finalized. With them, a large part of this experimental program will be completed. I will give the status of the measurements at long distances. I will then conclude the talk with a practical example on how the GDH data are used to connect the fundamental and effective descriptions of the strong force. Such example demonstrates how the generalized GDH program is bearing fruits.

  19. Estimating and Identifying Unspecified Correlation Structure for Longitudinal Data

    PubMed Central

    Hu, Jianhua; Wang, Peng; Qu, Annie

    2014-01-01

    Identifying correlation structure is important to achieving estimation efficiency in analyzing longitudinal data, and is also crucial for drawing valid statistical inference for large size clustered data. In this paper, we propose a nonparametric method to estimate the correlation structure, which is applicable for discrete longitudinal data. We utilize eigenvector-based basis matrices to approximate the inverse of the empirical correlation matrix and determine the number of basis matrices via model selection. A penalized objective function based on the difference between the empirical and model approximation of the correlation matrices is adopted to select an informative structure for the correlation matrix. The eigenvector representation of the correlation estimation is capable of reducing the risk of model misspecification, and also provides useful information on the specific within-cluster correlation pattern of the data. We show that the proposed method possesses the oracle property and selects the true correlation structure consistently. The proposed method is illustrated through simulations and two data examples on air pollution and sonar signal studies. PMID:26361433

  20. Spin structure of harmonically trapped one-dimensional atoms with spin-orbit coupling

    NASA Astrophysics Data System (ADS)

    Guan, Q.; Blume, D.

    2015-08-01

    We introduce a theoretical approach to determine the spin structure of harmonically trapped atoms with two-body zero-range interactions subject to an equal mixture of Rashba and Dresselhaus spin-orbit coupling created through Raman coupling of atomic hyperfine states. The spin structure of bosonic and fermionic two-particle systems with finite and infinite two-body interaction strength g is calculated. Taking advantage of the fact that the N -boson and N -fermion systems with infinitely large coupling strength g are analytically solvable for vanishing spin-orbit coupling strength kso and vanishing Raman coupling strength Ω , we develop an effective spin model that is accurate to second order in Ω for any kso and infinite g . The three- and four-particle systems are considered explicitly. It is shown that the effective spin Hamiltonian, which contains a Heisenberg exchange term and an anisotropic Dzyaloshinskii-Moriya exchange term, describes the transitions that these systems undergo with the change of kso as a competition between independent spin dynamics and nearest-neighbor spin interactions.

  1. Thermal spin transfer torque driven by ultrafast heat current in metallic spin-valve structures

    NASA Astrophysics Data System (ADS)

    Choi, Gyung-Min; Min, Byoung-Chul; Lee, Kyung-Jin; Cahill, David

    2015-03-01

    Spin transfer torque (STT), coupling of the angular momentum of the spin of electrons and the magnetization of a ferromagnet, enables the manipulation of nanomagnets with spin currents rather than magnetic fields. STT has been most often realized by passing electrical currents through magnetic layers. Generation of STT by passing a heat current through magnetic layers has been theoretically predicted. This so-called ``thermal STT'' relies on the transport of thermal energy, as opposed to the transport of electrical charge, and provides new functionality for device applications. Here, we provide direct evidence of thermal STT generated by ps time-scale heat currents on the order of 100 GW m-2. In metallic spin valve structures, the physical mechanism for thermal STT is the spin-dependent Seebeck effect (SDSE). We create ultrafast heat currents using ps duration pulses of laser light in the NM1/FM1/NM2/FM2 structure: FM1 acts as a spin generation layer by SDSE and FM2 acts as a spin detection layer by STT; NM1 acts as a heat absorbing layer and NM2 acts as a heat sink layer. The magnetization dynamics of FM2 are probed by time-resolved magneto-optic Kerr effect with a time resolution of 1 ps. By incorporating different ferromagnetic layers, which have different signs for SDSE, and varying the thickness of the heat sink layer, we are able to control the sign and magnitude of thermal spin torque.

  2. First-principles modeling of longitudinal spin fluctuations in itinerant electron antiferromagnets: High Néel temperature in the V3Al alloy

    NASA Astrophysics Data System (ADS)

    Khmelevskyi, Sergii

    2016-07-01

    The V3Al alloy with D O3 crystal structure belongs to the family of the very few metallic materials that exhibit a magnetically ordered state with a high ordering temperature (˜600 K) and consist only of nonmagnetic elements. We show that, similarly to the ferromagnetism in the fcc Ni (with ordering temperature at about 630 K), the antiferromagnetism in V3Al has itinerant character, and the high value of the Néel temperature is the result of the strong longitudinal spin fluctuations in the paramagnetic state. In order to develop an ab initio-based theory of the magnetic ordering at finite temperatures, we employ an effective magnetic Heisenberg-like Hamiltonian with varying values of the on-site magnetic moments. Using a set of approximations we map this model onto the results of the first-principle-based disordered local moment formalism and the magnetoforce theorem applied in the framework of the Korringa-Kohn-Rostoker method. Our high-temperature approach is shown to describe the experimental Néel temperature of V3Al very well and thus underlines the importance of the longitudinal spin-fluctuation mechanism of formation of the vanadium magnetic moment at high temperatures.

  3. Measurements of the Neutron Longitudinal Spin Asymmetry A1n and Flavor Decomposition in the Valence Quark Region

    SciTech Connect

    Flay, David J.

    2014-08-01

    The current data for the nucleon-virtual photon longitudinal spin asymmetry A1 on the proton and neutron have shown that the ratio of the polarized-to-unpolarized down-quarkparton distribution functions,Dd=d, tends towards -1/2 at large x, in disagreement with the perturbative QCD prediction that Dd/d approaches 1 but more in line with constituent quark models. As a part of experiment E06-014 in Hall A of Jefferson Lab, double-spin asymmetries were measured in the scattering of a longitudinally polarized electron beam of energies 4.74 and 5.89 GeV from a longitudinally and transversely polarized 3He target in the deep inelastic scattering and resonance region, allowing for the extraction of the neutron asymmetry An1 and the ratios Dd/d and Du/u. We will discuss our analysis of the data and present results for A1 and g1/F1 on both 3He and the neutron, and the resulting quark ratios for the up and down quarks in the kinematic range of 0.2

  4. Proton Spin Structure from Large Momentum Effective Theory

    NASA Astrophysics Data System (ADS)

    Zhang, Jian-Hui; Ji, Xiangdong; Zhao, Yong

    2016-08-01

    Recently a large momentum effective theory approach has been proposed to compute parton observables. We discuss its application to the spin structure of the proton. In particular, we explain how the partonic contribution to the proton spin in the Jaffe-Manohar sum rule can be computed within the large momentum effective theory framework.

  5. Measurement of Longitudinal Spin Asymmetries for Weak Boson Production in Polarized Proton-Proton Collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Balewski, J.; Banerjee, A.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Contin, G.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kosarzewski, L. K.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Olvitt, D. L.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szelezniak, M. A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zawisza, Y.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2014-08-01

    We report measurements of single- and double-spin asymmetries for W± and Z/γ* boson production in longitudinally polarized p+p collisions at √s =510 GeV by the STAR experiment at RHIC. The asymmetries for W± were measured as a function of the decay lepton pseudorapidity, which provides a theoretically clean probe of the proton's polarized quark distributions at the scale of the W mass. The results are compared to theoretical predictions, constrained by polarized deep inelastic scattering measurements, and show a preference for a sizable, positive up antiquark polarization in the range 0.05

  6. Single and double spin asymmetries for deeply virtual Compton scattering measured with CLAS and a longitudinally polarized proton target

    SciTech Connect

    Pisano, S.; Biselli, A.; Niccolai, S.; Seder, E.; Guidal, M.; Mirazita, M.; Adhikari, K. P.; Adikaram, D.; Amaryan, M. J.; Anderson, M. D.; Anefalos Pereira, S.; Avakian, H.; Ball, J.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Bosted, P.; Briscoe, B.; Brock, J.; Brooks, W. K.; Burkert, V. D.; Carlin, C.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Colaneri, L.; Cole, P. L.; Compton, N.; Contalbrigo, M.; Cortes, O.; Crabb, D. G.; Crede, V.; D' Angelo, A.; De Vita, R.; De Sanctis, E.; Deur, A.; Djalali, C.; Dupre, R.; Egiyan, H.; El Alaoui, A.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Fersch, R.; Filippi, A.; Fleming, J. A.; Fradi, A.; Garillon, B.; Garcon, M.; Ghandilyan, Y.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Griffioen, K. A.; Guo, L.; Hafidi, K.; Hanretty, C.; Hattawy, M.; Hicks, K.; Holtrop, M.; Hughes, S. M.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Jenkins, D.; Jiang, X.; Jo, H. S.; Joo, K.; Joosten, S.; Keith, C. D.; Keller, D.; Kim, A.; Kim, W.; Klein, F. J.; Kubarovsky, V.; Kuhn, S. E.; Lenisa, P.; Livingston, K.; Lu, H. Y.; MacCormick, M.; MacGregor, Ian J. D.; Mayer, M.; McKinnon, B.; Meekins, D. G.; Meyer, C. A.; Mokeev, V.; Montgomery, R. A.; Moody, C. I.; Munoz Camacho, C.; Nadel-Turonski, P.; Osipenko, M.; Ostrovidov, A. I.; Park, K.; Phelps, W.; Phillips, J. J.; Pogorelko, O.; Price, J. W.; Procureur, S.; Prok, Y.; Puckett, A. J. R.; Ripani, M.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Sabatie, F.; Salgado, C.; Schott, D.; Schumacher, R. A.; Skorodumina, I.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Sparveris, N.; Stepanyan, S.; Stoler, P.; Strauch, S.; Sytnik, V.; Tian, Ye; Tkachenko, S.; Turisini, M.; Ungaro, M.; Voutier, E.; Walford, N. K.; Watts, D. P.; Wei, X.; Weinstein, L. B.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z. W.; Zonta, I.

    2015-03-19

    Single-beam, single-target, and double-spin asymmetries for hard exclusive photon production on the proton e→p→e'p'γ are presented. The data were taken at Jefferson Lab using the CLAS detector and a longitudinally polarized 14NH3 target. The three asymmetries were measured in 165 4-dimensional kinematic bins, covering the widest kinematic range ever explored simultaneously for beam and target-polarization observables in the valence quark region. The kinematic dependences of the obtained asymmetries are discussed and compared to the predictions of models of Generalized Parton Distributions. As a result, the measurement of three DVCS spin observables at the same kinematic points allows a quasi-model-independent extraction of the imaginary parts of the H and H~ Compton Form Factors, which give insight into the electric and axial charge distributions of valence quarks in the proton.

  7. Neutron spin structure results from JLab Hall A

    SciTech Connect

    Zein-Eddine Meziani

    2004-02-01

    My presentation will focus on some of the latest results of the neutron spin physics program at Jefferson Laboratory in Hall A using a polarized 3He target. This program includes several completed experiments in which the spin structure functions of 3He were measured. The covered kinematic regions were these measurements were performed include the low Q2 resonance and inelastic regions and the high Q2 deep inelastic region. These experiments offer a ground for testing our understanding of the strong regime of quantum chromodynamics (QCD) through the determination of the neutron spin-dependent structure functions and their moments.

  8. Formulation of numerical procedures for dynamic analysis of spinning structures

    NASA Technical Reports Server (NTRS)

    Gupta, K. K.

    1986-01-01

    The paper presents the descriptions of recently developed numerical algorithms that prove to be useful for the solution of the free vibration problem of spinning structures. First, a generalized procedure for the computation of nodal centrifugal forces in a finite element owing to any specified spin rate is derived in detail. This is followed by a description of an improved eigenproblem solution procedure that proves to be economical for the free vibration analysis of spinning structures. Numerical results are also presented which indicate the efficacy of the currently developed procedures.

  9. High-Spin Structure of 102Ru

    NASA Astrophysics Data System (ADS)

    Sohler, D.; Timár, J.; Rainovski, G.; Joshi, P.; Starosta, K.; Fossan, D. B.; Molnár, J.; Wadsworth, R.; Algora, A.; Bednarczyk, P.; Curien, D.; Dombrádi, Zs.; Duchene, G.; Gizon, A.; Gizon, J.; Jenkins, D. G.; Koike, T.; Krasznahorkay, A.; Paul, E. S.; Raddon, P. M.; Scheurer, J. N.; Simons, A. J.; Vaman, C.; Wilkinson, A. R.; Zolnai, L.

    2005-11-01

    High-spin states in the nucleus 102Ru have been studied through the 96Zr(13C,α3n) reaction using the EUROBALL IV γ-ray spectrometer accompanied by the DIAMANT array for the detection of charged particles. All previously known bands have been extended to higher spins and additional bands have been found. Comparing the experimental Routhians and aligned angular momenta to the predictions of Woods-Saxon TRS calculations, vh11/2(d5/2,g7/2) configurations have been assigned to the observed negative-parity bands.

  10. High-Spin Structure of 102Ru

    SciTech Connect

    Sohler, D.; Timar, J.; Molnar, J.; Algora, A.; Dombradi, Zs.; Krasznahorkay, A.; Zolnai, L.; Rainovski, G.; Joshi, P.; Wadsworth, R.; Jenkins, D.G.; Raddon, P.M.; Simons, A.J.; Wilkinson, A.R.; Starosta, K.; Fossan, D.B.; Bednarczyk, P.; Curien, D.; Duchene, G.; Gizon, A.

    2005-11-21

    High-spin states in the nucleus 102Ru have been studied through the 96Zr(13C,{alpha}3n) reaction using the EUROBALL IV {gamma}-ray spectrometer accompanied by the DIAMANT array for the detection of charged particles. All previously known bands have been extended to higher spins and additional bands have been found. Comparing the experimental Routhians and aligned angular momenta to the predictions of Woods-Saxon TRS calculations, vh11/2(d5/2,g7/2) configurations have been assigned to the observed negative-parity bands.

  11. Nucleon Spin Structure at Low Energies

    SciTech Connect

    Krebs, H.; Bernard, V.; Meissner, Ulf-G.

    2009-07-27

    We apply chiral effective field theory with explicit DELTA-1232) degrees of freedom to study double virtual Compton scattering at the photon point. Generalized spin polarizabilities are calculated up to order epsilon{sup 3} in the covariant small scale expansion. Systematic inclusion of DELTA degrees of freedom drastically improves the theoretical predictions.

  12. Spin wave band structure of artificial square ices

    NASA Astrophysics Data System (ADS)

    Iacocca, Ezio; Gliga, Sebastian; Stamps, Robert; Heinonen, Olle

    Artificial square spin ices are structures composed of magnetic elements located on the sites of a geometrically frustrated, two-dimensional square lattice. Using a semi-analytical approach, we show that square spin ices exhibit a rich spin wave band structure that is tunable both by external magnetic fields and the magnetic state of individual elements. Internal degrees of freedom can give rise to equilibrium states with bent magnetization at the edges of each element, leading to characteristic excitations; in the presence of magnetostatic interactions these form separate bands analogous to impurity bands in semiconductors. Full-scale micromagnetic simulations corroborate our semi-analytical approach. This study shows that the magnon spectra, and therefore group and phase velocities and band gap, can be manipulated by external fields, temperature, or more sophisticated techniques such as using spin torque on individual elements, and suggesting that artificial square spin ices can be used as metamaterials for spin waves. Our results close the gap between the research fields of artificial spin ices and magnonics. E.I. acknowledges the Swedish Research Council, Reg.No. 637-2014-6863. The work by O.H. was funded by the Department of Energy Office of Science, Materials Sciences and Engineering Division. The work by R.L.S. was funded by EPSRC EP/L002922/1.

  13. High-spin structure of 95Pd

    NASA Astrophysics Data System (ADS)

    Mărginean, R.; Rusu, C.; Mărginean, N.; Bucurescu, D.; Ur, C. A.; de Angelis, G.; Axiotis, M.; Bazzacco, D.; Farnea, E.; Gadea, A.; Ionescu-Bujor, M.; Iordăchescu, A.; Krolas, W.; Kröll, Th.; Lenzi, S. M.; Lunardi, S.; Napoli, D. R.; Alvarez, C. Rossi; Wrzesinski, J.

    2012-09-01

    The level scheme of the neutron-deficient nucleus 95Pd has been studied with the 58Ni + 40Ca fusion-evaporation reaction at 135 MeV with the GASP γ-ray array, the ISIS silicon ball, and the N-ring neutron detector. Excited levels with spins at least up to (45)/(2)ℏ are reported for both parities. The observed experimental data are compared to large-scale shell-model calculations.

  14. Overview of Spin Structure Program at Jefferson Lab

    SciTech Connect

    Prok, Yelena

    2013-04-01

    An extensive experimental program to study spin physics at low and moderate four - momentum transfer, Q{sup 2}, has been pursued by Jefferson Lab during the last 15 years, with complementary measurements taking place in all 3 experimental halls. Our inclusive data with high statistical precision and extensive kinematic coverage allow us to better constrain the polarized parton distributions, to accurately determine various moments of spin structure functions, to test the spin content of valent quarks, and to investigate the effects of resonance excitations and higher twist, dominant in this kinematic regime. Our recent semi-inclusive and exclusive measurements have given us new avenues of exploration, and inspired a new generation of experiments planned with 12 GeV beam. Highlights from 6 GeV experimental program are discussed, along with the 12 GeV data projections, and expected impact on the NLO global fits and phenomenological models of valent spin structure.

  15. Interaction between spin-wave excitations and pure spin currents in magnetic structures

    NASA Astrophysics Data System (ADS)

    Azevedo, Antonio

    2012-02-01

    The generation of pure spin current (PSC) in magnetic structures has attracted much attention not only for its fundamental importance in spintronics, but also because it opens up potential applications. One of the most exciting aspects of this area is the interplay between spin-waves (SW) and PSC. Here we report experimental results in which the PSC, generated by both spin pumping (SPE) [1] and spin Seebeck (SSE) [2] effects, can exert a spin-transfer torque sufficient to compensate the SW relaxation in yttrium iron garnet (YIG)/non-magnetic structures. By measuring the propagation of SW packets in single-crystal YIG films we were able to observe the amplification of volume and magnetostatic modes (MSW) by both SSE and SHE [3,4]. The excitation and detection of the SW packets is carried out by using a MSW delay line device. In both cases the amplification is attributed to the spin-transfer torque due to PSC generated by SSE as well as SHE. It will also be presented new results in which PSC are simultaneously excited by SSE and SPE effects in YIG films. While the spin current generated by SPE is obtained by exciting the ferromagnetic resonance (FMR) of the YIG film, the spin current due to SSE is created by applying a temperature gradient along the film plane. The effect of the superposition of both spin currents is characterized by measuring the spin Hall voltage (VH) along thin strips of Pt deposited on top of the YIG films. Whereas VH corresponding to the uniform FMR is amplified due the SSE the voltages corresponding to the other magnetostatic spin-wave modes are attenuated [5]. [4pt] [1] Y. Tserkovnyak, et al., Rev. Mod. Phys. 77, 1375 (2005).[0pt] [2] K. Uchida, et al., Nature 455, 778 (2008).[0pt] [3] E. Padr'on-Hern'andez, A. Azevedo, and S. M. Rezende, Phys. Rev. Letts., 107, 197203 (2011).[0pt] [4] E. Padr'on-Hern'andez, A. Azevedo, and S. M. Rezende, Appl. Phys. Letts., 99 (2011) in press.[0pt] [5] G.L. da Silva, L.H. Vilela-Leão, S. M. Rezende and A

  16. Spin Structure Functions in a Covariant Spectator Quark Model

    SciTech Connect

    G. Ramalho, Franz Gross and M. T. Peña

    2010-12-01

    We apply the covariant spectator quark–diquark model, already probed in the description of the nucleon elastic form factors, to the calculation of the deep inelastic scattering (DIS) spin-independent and spin-dependent structure functions of the nucleon. The nucleon wave function is given by a combination of quark–diquark orbital states, corresponding to S, D and P-waves. A simple form for the quark distribution function associated to the P and D waves is tested.

  17. Singularities of the dynamical structure factors of the spin-1/2 XXX chain at finite magnetic field

    NASA Astrophysics Data System (ADS)

    Carmelo, J. M. P.; Sacramento, P. D.; Machado, J. D. P.; Campbell, D. K.

    2015-10-01

    We study the longitudinal and transverse spin dynamical structure factors of the spin-1/2 XXX chain at finite magnetic field h, focusing in particular on the singularities at excitation energies in the vicinity of the lower thresholds. While the static properties of the model can be studied within a Fermi-liquid like description in terms of pseudoparticles, our derivation of the dynamical properties relies on the introduction of a form of the ‘pseudofermion dynamical theory’ (PDT) of the 1D Hubbard model suitably modified for the spin-only XXX chain and other models with two pseudoparticle Fermi points. Specifically, we derive the exact momentum and spin-density dependences of the exponents {{\\zeta}τ}(k) controlling the singularities for both the longitudinal ≤ft(τ =l\\right) and transverse ≤ft(τ =t\\right) dynamical structure factors for the whole momentum range k\\in ]0,π[ , in the thermodynamic limit. This requires the numerical solution of the integral equations that define the phase shifts in these exponents expressions. We discuss the relation to neutron scattering and suggest new experiments on spin-chain compounds using a carefully oriented crystal to test our predictions.

  18. Singularities of the dynamical structure factors of the spin-1/2 XXX chain at finite magnetic field.

    PubMed

    Carmelo, J M P; Sacramento, P D; Machado, J D P; Campbell, D K

    2015-10-14

    We study the longitudinal and transverse spin dynamical structure factors of the spin-1/2 XXX chain at finite magnetic field h, focusing in particular on the singularities at excitation energies in the vicinity of the lower thresholds. While the static properties of the model can be studied within a Fermi-liquid like description in terms of pseudoparticles, our derivation of the dynamical properties relies on the introduction of a form of the 'pseudofermion dynamical theory' (PDT) of the 1D Hubbard model suitably modified for the spin-only XXX chain and other models with two pseudoparticle Fermi points. Specifically, we derive the exact momentum and spin-density dependences of the exponents ζ(τ)(k) controlling the singularities for both the longitudinal (τ = l) and transverse (τ = t) dynamical structure factors for the whole momentum range k ∈ ]0,π[, in the thermodynamic limit. This requires the numerical solution of the integral equations that define the phase shifts in these exponents expressions. We discuss the relation to neutron scattering and suggest new experiments on spin-chain compounds using a carefully oriented crystal to test our predictions. PMID:26403307

  19. Heteronuclear transverse and longitudinal relaxation in AX4 spin systems: Application to 15N relaxations in 15NH4+

    PubMed Central

    Werbeck, Nicolas D.; Hansen, D. Flemming

    2014-01-01

    The equations that describe the time-evolution of transverse and longitudinal 15N magnetisations in tetrahedral ammonium ions, 15NH4+, are derived from the Bloch-Wangsness-Redfield density operator relaxation theory. It is assumed that the relaxation of the spin-states is dominated by (1) the intra-molecular 15N–1H and 1H–1H dipole–dipole interactions and (2) interactions of the ammonium protons with remote spins, which also include the contribution to the relaxations that arise from the exchange of the ammonium protons with the bulk solvent. The dipole–dipole cross-correlated relaxation mechanisms between each of the 15N–1H and 1H–1H interactions are explicitly taken into account in the derivations. An application to 15N-ammonium bound to a 41 kDa domain of the protein DnaK is presented, where a comparison between experiments and simulations show that the ammonium ion rotates rapidly within its binding site with a local correlation time shorter than approximately 1 ns. The theoretical framework provided here forms the basis for further investigations of dynamics of AX4 spin systems, with ammonium ions in solution and bound to proteins of particular interest. PMID:25128779

  20. Moments of Spin Structure Functions: Sum Rules and Polarizabilities

    SciTech Connect

    Jian-Ping Chen

    2010-10-01

    Nucleon structure study is one of the most important research areas in modern physics and has challenged us for decades. Spin has played an essential role and often brought surprises and puzzles to the investigation of the nucleon structure and the strong interaction. New experimental data on nucleon spin structure at low to intermediate momentum transfers combined with existing high momentum transfer data offer a comprehensive picture in the strong region of the interaction and of the transition region from the strong to the asymptotic-free region. Insight for some aspects of the theory for the strong interaction, Quantum Chromodynamics (QCD), is gained by exploring lower moments of spin structure functions and their corresponding sum rules (i.e. the Bjorken, Burkhardt-Cottingham, Gerasimov-Drell-Hearn (GDH), and the generalized GDH). These moments are expressed in terms of an operator-product expansion using quark and gluon degrees of freedom at moderately large momentum transfers.

  1. Interfacial Structure Dependent Spin Mixing Conductance in Cobalt Thin Films.

    PubMed

    Tokaç, M; Bunyaev, S A; Kakazei, G N; Schmool, D S; Atkinson, D; Hindmarch, A T

    2015-07-31

    Enhancement of Gilbert damping in polycrystalline cobalt thin-film multilayers of various thicknesses, overlayered with copper or iridium, was studied in order to understand the role of local interface structure in spin pumping. X-ray diffraction indicates that cobalt films less than 6 nm thick have strong fcc(111) texture while thicker films are dominated by hcp(0001) structure. The intrinsic damping for cobalt thicknesses above 6 nm is weakly dependent on cobalt thickness for both overlayer materials, and below 6 nm the iridium overlayers show higher damping enhancement compared to copper overlayers, as expected due to spin pumping. The interfacial spin mixing conductance is significantly enhanced in structures where both cobalt and iridium have fcc(111) structure in comparison to those where the cobalt layer has subtly different hcp(0001) texture at the interface. PMID:26274431

  2. On presymplectic structures for massless higher-spin fields

    NASA Astrophysics Data System (ADS)

    Sharapov, Alexey A.

    2016-06-01

    A natural presymplectic structure for non-Lagrangian equations of motion governing the dynamics of free higher-spin fields in four-dimensional anti-de Sitter space is proposed. This presymplectic structure is then used in the derivation of the conserved currents associated with the relativistic invariance and to the construction of local functionals of fields that are gauge invariant on shell.

  3. Rich eight-branch spectrum of the oblique propagating longitudinal waves in partially spin-polarized electron-positron-ion plasmas

    NASA Astrophysics Data System (ADS)

    Andreev, Pavel A.; Iqbal, Z.

    2016-03-01

    We consider the separate spin evolution of electrons and positrons in electron-positron and electron-positron-ion plasmas. We consider the oblique propagating longitudinal waves in these systems. Working in a regime of high-density n0˜1027cm-3 and high-magnetic-field B0=1010 G, we report the presence of the spin-electron acoustic waves and their dispersion dependencies. In electron-positron plasmas, similarly to the electron-ion plasmas, we find one spin-electron acoustic wave (SEAW) at the propagation parallel or perpendicular to the external field and two spin-electron acoustic waves at the oblique propagation. At the parallel or perpendicular propagation of the longitudinal waves in electron-positron-ion plasmas, we find four branches: the Langmuir wave, the positron-acoustic wave, and a pair of waves having spin nature, they are the SEAW and the wave discovered in this paper, called the spin-electron-positron acoustic wave (SEPAW). At the oblique propagation we find eight longitudinal waves: the Langmuir wave, the Trivelpiece--Gould wave, a pair of positron-acoustic waves, a pair of SEAWs, and a pair of SEPAWs. Thus, for the first time, we report the existence of the second positron-acoustic wave existing at the oblique propagation and the existence of SEPAWs.

  4. Spin Structure of the Nucleon - Status and Recent Results

    SciTech Connect

    Kuhn, Sebastian; Chen, Jian-Ping; Leader, Elliot

    2009-07-01

    After the initial discovery of the so-called "spin crisis in the parton model" in the 1980s, a large set of polarization data in deep inelastic lepton-nucleon scattering was collected at labs like SLAC, DESY and CERN. More recently, new high precision data at large $x$ and in the resonance region have come from experiments at Jefferson Lab. These data, in combination with the earlier ones, allow us to study in detail the polarized parton densities, the $Q^2$ dependence of various moments of spin structure functions, the duality between deep inelastic and resonance data, and the nucleon structure in the valence quark region. Together with complementary data from HERMES, RHIC and COMPASS, we can put new limits on the flavor decomposition and the gluon contribution to the nucleon spin. In this report, we provide an overview of our present knowledge of the nucleon spin structure and give an outlook on future experiments. We focus in particular on the spin structure functions $g_

  5. Spin structure of spin-1/2 baryon and spinless meson production amplitudes in photonic and hadronic reactions

    SciTech Connect

    Nakayama, K.; Love, W.G.

    2005-09-01

    The most general spin structures of the spin-1/2 baryon and spinless meson production operator for both photon and nucleon induced reactions are derived from the partial-wave expansions of these reaction amplitudes. The present method provides the coefficients multiplying each spin operator in terms of the partial-wave matrix elements. The result should be useful in studies of these reactions based on partial-wave analyses, especially, when spin observables are considered.

  6. A Spin-Light Polarimeter for Multi-GeV Longitudinally Polarized Electron Beams

    SciTech Connect

    Mohanmurthy, Prajwal; Dutta, Dipangkar

    2014-02-01

    The physics program at the upgraded Jefferson Lab (JLab) and the physics program envisioned for the proposed electron-ion collider (EIC) include large efforts to search for interactions beyond the Standard Model (SM) using parity violation in electroweak interactions. These experiments require precision electron polarimetry with an uncertainty of < 0.5 %. The spin dependent Synchrotron radiation, called "spin-light," can be used to monitor the electron beam polarization. In this article we develop a conceptual design for a "spin-light" polarimeter that can be used at a high intensity, multi-GeV electron accelerator. We have also built a Geant4 based simulation for a prototype device and report some of the results from these simulations.

  7. Engineering hybrid Co-picene structures with variable spin coupling

    NASA Astrophysics Data System (ADS)

    Zhou, Chunsheng; Shan, Huan; Li, Bin; Zhao, Aidi; Wang, Bing

    2016-04-01

    We report on the in situ engineering of hybrid Co-picene magnetic structures with variable spin coupling using a low-temperature scanning tunneling microscope. Single picene molecules adsorbed on Au(111) are manipulated to accommodate individual Co atoms one by one, forming stable artificial hybrid structures with magnetism introduced by the Co atoms. By monitoring the evolution of the Kondo effect at each site of Co atom, we found that the picene molecule plays an important role in tuning the spin coupling between individual Co atoms, which is confirmed by theoretical calculations based on the density-functional theory. Our findings indicate that the hybrid metal-molecule structures with variable spin coupling on surfaces can be artificially constructed in a controlled manner.

  8. Spin Testing of Superalloy Disks With Dual Grain Structure

    NASA Technical Reports Server (NTRS)

    Hefferman, Tab M.

    2006-01-01

    This 24-month program was a joint effort between Allison Advanced Development Company (AADC), General Electric Aircraft (GEAE), and NASA Glenn Research Center (GRC). AADC led the disk and spin hardware design and analysis utilizing existing Rolls-Royce turbine disk forging tooling. Testing focused on spin testing four disks: two supplied by GEAE and two by AADC. The two AADC disks were made of Alloy 10, and each was subjected to a different heat treat process: one producing dual microstructure with coarse grain size at the rim and fine grain size at the bore and the other produced single fine grain structure throughout. The purpose of the spin tests was to provide data for evaluation of the impact of dual grain structure on disk overspeed integrity (yielding) and rotor burst criteria. The program culminated with analysis and correlation of the data to current rotor overspeed criteria and advanced criteria required for dual structure disks.

  9. Anisotropies and spin dynamics in ultrathin magnetic multilayer structures

    NASA Astrophysics Data System (ADS)

    Kardasz, Bartlomiej

    High quality magnetic films were prepared by Molecular Beam Epitaxy (MBE) using Thermal Deposition (TD) and Pulse Laser Deposition (PLD) techniques. Ferromagnetic Resonance (FMR) and Mossbauer studies have shown that the Fe films prepared by PLD exhibited a more intermixed interface lattice structure than those prepared by TD. Dramatic decrease of the in-plane interface uniaxial anisotropy for the PLD films compared to those prepared by TD has shown that the in-plane uniaxial anisotropy is caused by magnetoelasticity driven by the Fe/GaAs(001) interface lattice shear. Magnetization dynamics of the ultrathin Fe/Au,Ag/Fe films was studied using Time-Resolved Magneto-Optical Kerr Effect (TRMOKE) and FMR in the frequency range from 1 to 73 GHz. The Gilbert damping was studied in the Au/Fe/GaAs(001) structures as a function of the Fe and Au layer thickness, respectively. The observed increase in magnetic damping in the Fe film covered with thick Au capping layers was explained by spin pumping at the Fe/Au interface accompanied by spin relaxation and diffusion of the accumulated spin density in the Au layer. The spin diffusion length in Au was found to be 34 nm at room temperature. Significant increase of the Gilbert damping was observed in the Au/Fe/GaAs structures with decreasing Fe film thickness. Its origin lies in the additional damping at the Fe/GaAs interface. Direct detection of the spin current propagating across the Ag spacer in Fe/Ag,Au/Fe/GaAs(001) structures was carried out with stroboscopic TRMOKE measurements. The Fe layer grown on GaAs served as a spin pumping source and the Fe layer grown on the Au,Ag spacer was used as a probe for detection of the spin current propagating across the Au and Ag spacers. The experimental results were interpreted using selfconsistent solution of the Landau Lifshitz Gilbert (LLG) equations of motion with the spin diffusion equation for the accumulated spin density in the Au and Ag spacers. The spin diffusion length in Ag was

  10. Longitudinal Double Spin Asymmetries in Heavy Flavor Production in Polarized p+p Collisions at {radical}(s) = 200 GeV

    SciTech Connect

    Wang, Xiaorong

    2009-08-04

    One of the main goals of the RHIC spin program is to determine the contribution of gluons to the proton spin. At RHIC energies, heavy quark (charm and beauty) production is expected to be dominated by gluon-gluon interactions, so a measurement of the double longitudinal spin asymmetry A{sub LL} in heavy quark production in polarized p+p collisions directly probes the polarized gluon distribution inside the proton. We present the latest results on an A{sub LL} measurement for J/{psi} and open charm production measured by the PHENIX detector.

  11. Longitudinal double-spin asymmetry for inclusive jet production in vec p + vec p collisions at sqrt s = 200 GeV

    SciTech Connect

    STAR Coll

    2007-10-07

    We report a new STAR measurement of the longitudinal double-spin asymmetry A{sub LL} for inclusive jet production at mid-rapidity in polarized p + p collisions at a center-of-mass energy of {radical}s = 200 GeV. The data, which cover jet transverse momenta 5 < p{sub T} < 30 GeV/c, are substantially more precise than previous measurements. They provide significant new constraints on the gluon spin contribution to the nucleon spin through the comparison to predictions derived from one global fit of polarized deep-inelastic scattering measurements.

  12. Longitudinal double-spin asymmetry for inclusive jet production in p[over -->] + p[over -->] collisions at sqrt[s]=200 GeV.

    PubMed

    Abelev, B I; Aggarwal, M M; Ahammed, Z; Anderson, B D; Arkhipkin, D; Averichev, G S; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Baumgart, S; Belaga, V V; Bellingeri-Laurikainen, A; Bellwied, R; Benedosso, F; Betts, R R; Bhardwaj, S; Bhasin, A; Bhati, A K; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Blyth, S-L; Bombara, M; Bonner, B E; Botje, M; Bouchet, J; Brandin, A V; Burton, T P; Bystersky, M; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Callner, J; Catu, O; Cebra, D; Cervantes, M C; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, J Y; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chung, S U; Clarke, R F; Codrington, M J M; Coffin, J P; Cormier, T M; Cosentino, M R; Cramer, J G; Crawford, H J; Das, D; Dash, S; Daugherity, M; de Moura, M M; Dedovich, T G; Dephillips, M; Derevschikov, A A; Didenko, L; Dietel, T; Djawotho, P; Dogra, S M; Dong, X; Drachenberg, J L; Draper, J E; Du, F; Dunin, V B; Dunlop, J C; Dutta Mazumdar, M R; Edwards, W R; Efimov, L G; Elhalhuli, E; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Fatemi, R; Fedorisin, J; Feng, A; Filip, P; Finch, E; Fine, V; Fisyak, Y; Fu, J; Gagliardi, C A; Gaillard, L; Ganti, M S; Garcia-Solis, E; Ghazikhanian, V; Ghosh, P; Gorbunov, Y N; Gos, H; Grebenyuk, O; Grosnick, D; Grube, B; Guertin, S M; Guimaraes, K S F F; Gupta, A; Gupta, N; Haag, B; Hallman, T J; Hamed, A; Harris, J W; He, W; Heinz, M; Henry, T W; Heppelmann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffman, A M; Hoffmann, G W; Hofman, D J; Hollis, R S; Horner, M J; Huang, H Z; Hughes, E W; Humanic, T J; Igo, G; Iordanova, A; Jacobs, P; Jacobs, W W; Jakl, P; Jones, P G; Judd, E G; Kabana, S; Kang, K; Kapitan, J; Kaplan, M; Keane, D; Kechechyan, A; Kettler, D; Khodyrev, V Yu; Kiryluk, J; Kisiel, A; Kislov, E M; Klein, S R; Knospe, A G; Kocoloski, A; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kouchpil, V; Kowalik, K L; Kravtsov, P; Kravtsov, V I; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kurnadi, P; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lapointe, S; Laue, F; Lauret, J; Lebedev, A; Lednicky, R; Lee, C-H; Lehocka, S; Levine, M J; Li, C; Li, Q; Li, Y; Lin, G; Lin, X; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, J; Liu, L; Ljubicic, T; Llope, W J; Longacre, R S; Love, W A; Lu, Y; Ludlam, T; Lynn, D; Ma, G L; Ma, J G; Ma, Y G; Mahapatra, D P; Majka, R; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Martin, L; Matis, H S; Matulenko, Yu A; McShane, T S; Meschanin, A; Millane, J; Miller, M L; Minaev, N G; Mioduszewski, S; Mischke, A; Mitchell, J; Mohanty, B; Morozov, D A; Munhoz, M G; Nandi, B K; Nattrass, C; Nayak, T K; Nelson, J M; Nepali, C; Netrakanti, P K; Nogach, L V; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Olson, D; Pachr, M; Pal, S K; Panebratsev, Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevoztchikov, V; Perkins, C; Peryt, W; Phatak, S C; Planinic, M; Pluta, J; Poljak, N; Porile, N; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Pruthi, N K; Putschke, J; Qattan, I A; Raniwala, R; Raniwala, S; Ray, R L; Relyea, D; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Russcher, M J; Sahoo, R; Sakrejda, I; Sakuma, T; Salur, S; Sandweiss, J; Sarsour, M; Sazhin, P S; Schambach, J; Scharenberg, R P; Schmitz, N; Seger, J; Selyuzhenkov, I; Seyboth, P; Shabetai, A; Shahaliev, E; Shao, M; Sharma, M; Shen, W Q; Shimanskiy, S S; Sichtermann, E P; Simon, F; Singaraju, R N; Skoby, M J; Smirnov, N; Snellings, R; Sorensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Staszak, D; Stock, R; Strikhanov, M; Stringfellow, B; Suaide, A A P; Suarez, M C; Subba, N L; Sumbera, M; Sun, X M; Sun, Z; Surrow, B; Symons, T J M; Szanto de Toledo, A; Takahashi, J; Tang, A H; Tarnowsky, T; Thomas, J H; Timmins, A R; Timoshenko, S; Tokarev, M; Trainor, T A; Tram, V N; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Van Buren, G; van der Kolk, N; van Leeuwen, M; Vander Molen, A M; Varma, R; Vasilevski, I M; Vasiliev, A N; Vernet, R; Vigdor, S E; Viyogi, Y P; Vokal, S; Voloshin, S A; Wada, M; Waggoner, W T; Wang, F; Wang, G; Wang, J S; Wang, X L; Wang, Y; Webb, J C; Westfall, G D; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wu, J; Wu, Y; Xu, N; Xu, Q H; Xu, Z; Yepes, P; Yoo, I-K; Yue, Q; Yurevich, V I; Zawisza, M; Zhan, W; Zhang, H; Zhang, W M; Zhang, Y; Zhang, Z P; Zhao, Y; Zhong, C; Zhou, J; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N; Zuo, J X

    2008-06-13

    We report a new STAR measurement of the longitudinal double-spin asymmetry A(LL) for inclusive jet production at midrapidity in polarized p + p collisions at a center-of-mass energy of sqrt[s]=200 GeV. The data, which cover jet transverse momenta 5spin contribution to the nucleon spin through the comparison to predictions derived from one global fit to polarized deep-inelastic scattering measurements. PMID:18643488

  13. Longitudinal double-spin asymmetry for inclusive jet production in p(pol) + p(pol) collisions at {radical}{ovr s} = 200 GeV.

    SciTech Connect

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Anderson, B. D.; Arkhipkin, D.; Krueger, K.; Spinka, H. M.; Underwood, D. G.; STAR Collaboration; High Energy Physics; Univ. of Illinois; Panjab Univ.; Variable Energy Cyclotron Centre; Kent State Univ.; Particle Physic Lab.

    2008-01-01

    We report a new STAR measurement of the longitudinal double-spin asymmetry A{sub LL} for inclusive jet production at midrapidity in polarized p+p collisions at a center-of-mass energy of {radical} = 200 GeV. The data, which cover jet transverse momenta 5 < p{sub T} < 30 GeV/c, are substantially more precise than previous measurements. They provide significant new constraints on the gluon spin contribution to the nucleon spin through the comparison to predictions derived from one global fit to polarized deep-inelastic scattering measurements.

  14. Spin Echo Attenuation of Restricted Diffusion as a Discord of Spin Phase Structure

    PubMed

    Stepisnik

    1998-04-01

    By using the particle probability density we analyze the spin echo attenuation of particles, diffusing in a bounded region. It provides a means to expand a nonuniform spin phase distribution into a series of waves that characterize the geometry and boundary conditions of confinement. Random motion disrupts the initial phase structure created by applied gradients and consequently discords its structure waves. By assuming the spin phase fluctuation and/or the randomness of spin phase distribution in the subensemble as a Gaussian stochastic process, we derive a new analytical expression for the echo attenuation related to the particle velocity correlation. For a diffusion in porous structure we get the expression featuring the same "diffusive diffraction" patterns as those being found and explained by P. T. Callaghan and A. Coy ("Principles of Nuclear Magnetic Resonance Microscopy," Oxford Univ. Press, Oxford (1991); J. Chem. Phys. 101, 4599-4609 (1994)) with the use of propagator theory. With the new approach we cast a new light on the phenomena and derive analitically how the diffusive diffractions appear when the sequence of finite or even modulated gradients are applied. The method takes into account the non-Markovian character of restricted diffusion, and therefore the echo dependence on the diffusion lengths and on the strength of applied gradient differs from the results of authors assuming the Markovian diffusion either by dealing with the diffusion propagators or by the computer simulation of Fick's diffusion. Copyright 1998 Academic Press. PMID:9571110

  15. Measurement of longitudinal spin asymmetries for weak boson production in polarized proton-proton collisions at RHIC.

    PubMed

    Adamczyk, L; Adkins, J K; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Alford, J; Anson, C D; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Balewski, J; Banerjee, A; Beavis, D R; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Borowski, W; Bouchet, J; Brandin, A V; Brovko, S G; Bültmann, S; Bunzarov, I; Burton, T P; Butterworth, J; Caines, H; Calderón de la Barca Sánchez, M; Campbell, J M; Cebra, D; Cendejas, R; Cervantes, M C; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, L; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chwastowski, J; Codrington, M J M; Contin, G; Cramer, J G; Crawford, H J; Cui, X; Das, S; Davila Leyva, A; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; Derradi de Souza, R; Dhamija, S; di Ruzza, B; Didenko, L; Dilks, C; Ding, F; Djawotho, P; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Engle, K S; Eppley, G; Eun, L; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Fedorisin, J; Filip, P; Finch, E; Fisyak, Y; Flores, C E; Gagliardi, C A; Gangadharan, D R; Garand, D; Geurts, F; Gibson, A; Girard, M; Gliske, S; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, A; Gupta, S; Guryn, W; Haag, B; Hamed, A; Han, L-X; Haque, R; Harris, J W; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, B; Huang, H Z; Huang, X; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Kesich, A; Khan, Z H; Kikola, D P; Kisel, I; Kisiel, A; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Kosarzewski, L K; Kotchenda, L; Kraishan, A F; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; LeVine, M J; Li, C; Li, W; Li, X; Li, X; Li, Y; Li, Z M; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, G L; Ma, Y G; Madagodagettige Don, D M M D; Mahapatra, D P; Majka, R; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; McShane, T S; Minaev, N G; Mioduszewski, S; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nelson, J M; Nigmatkulov, G; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Ohlson, A; Okorokov, V; Oldag, E W; Olvitt, D L; Pachr, M; Page, B S; Pal, S K; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlak, T; Pawlik, B; Pei, H; Perkins, C; Peryt, W; Pile, P; Planinic, M; Pluta, J; Poljak, N; Poniatowska, K; Porter, J; Poskanzer, A M; Pruthi, N K; Przybycien, M; Pujahari, P R; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, R; Raniwala, S; Ray, R L; Riley, C K; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ross, J F; Roy, A; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandweiss, J; Sangaline, E; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Singaraju, R N; Skoby, M J; Smirnov, D; Smirnov, N; Solanki, D; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Sun, X; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; Szelezniak, M A; Takahashi, J; Tang, A H; Tang, Z; Tarnowsky, T; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Trzeciak, B A; Tsai, O D; Turnau, J; Ullrich, T; Underwood, D G; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Vertesi, R; Videbæk, F; Viyogi, Y P; Vokal, S; Vossen, A; Wada, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, X L; Wang, Y; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xiao, Z; Xie, W; Xin, K; Xu, H; Xu, J; Xu, N; Xu, Q H; Xu, Y; Xu, Z; Yan, W; Yang, C; Yang, Y; Yang, Y; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Yu, N; Zawisza, Y; Zbroszczyk, H; Zha, W; Zhang, J B; Zhang, J L; Zhang, S; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, F; Zhao, J; Zhong, C; Zhu, X; Zhu, Y H; Zoulkarneeva, Y; Zyzak, M

    2014-08-15

    We report measurements of single- and double-spin asymmetries for W^{±} and Z/γ^{*} boson production in longitudinally polarized p+p collisions at sqrt[s]=510  GeV by the STAR experiment at RHIC. The asymmetries for W^{±} were measured as a function of the decay lepton pseudorapidity, which provides a theoretically clean probe of the proton's polarized quark distributions at the scale of the W mass. The results are compared to theoretical predictions, constrained by polarized deep inelastic scattering measurements, and show a preference for a sizable, positive up antiquark polarization in the range 0.05

  16. Spin-orbit interaction in relativistic nuclear structure models

    NASA Astrophysics Data System (ADS)

    Ebran, J.-P.; Mutschler, A.; Khan, E.; Vretenar, D.

    2016-08-01

    Relativistic self-consistent mean-field (SCMF) models naturally account for the coupling of the nucleon spin to its orbital motion, whereas nonrelativistic SCMF methods necessitate a phenomenological ansatz for the effective spin-orbit potential. Recent experimental studies aim to explore the isospin properties of the effective spin-orbit interaction in nuclei. SCMF models are very useful in the interpretation of the corresponding data; however, standard relativistic mean-field and nonrelativistic Hartree-Fock models use effective spin-orbit potentials with different isovector properties, mainly because exchange contributions are not treated explicitly in the former. The impact of exchange terms on the effective spin-orbit potential in relativistic mean-field models is analyzed, and it is shown that it leads to an isovector structure similar to the one used in standard nonrelativistic Hartree-Fock models. Data on the isospin dependence of spin-orbit splittings in spherical nuclei could be used to constrain the isovector-scalar channel of relativistic mean-field models. The reproduction of the empirical kink in the isotope shifts of even Pb nuclei by relativistic effective interactions points to the occurrence of pseudospin symmetry in the single-neutron spectra in these nuclei.

  17. Spectral control of spin qubits in diamond photonic structures

    NASA Astrophysics Data System (ADS)

    Acosta, Victor; Santori, Charles; Faraon, Andrei; Huang, Zhihong; Beausoleil, Raymond

    2012-06-01

    Integrated photonic networks based on cavity-coupled spin impurities offer a promising platform for scalable quantum computing. A key ingredient for this technology involves heralding entanglement by interfering indistinguishable photons emitted by pairs of identical spin qubits. The nitrogen-vacancy (NV) center in diamond is an attractive candidate for such a spin-photon interface, as it exhibits long-lived electronic spin coherence, rapid spin manipulation and readout, and the coexistence of both robust cycling and spin-altering Lambda-type transitions. We discuss current research in our lab to control the spectral properties of single NV centers by dynamic Stark tuning [1] and cavity Purcell enhancement [2]. In particular, we report progress on fabricating photonic structures in ultra-pure diamond, where NV centers are likely to have favorable optical properties. [4pt] [1] V. M. Acosta et al., Dynamic stabilization of the optical resonances of single nitrogen-vacancy centers in diamond, arXiv:1112.5490v1 [quant-ph]. [0pt] [2] A. Faraon et al., Coupling of nitrogen-vacancy centers to photonic crystal cavities in monocrystalline diamond, Submitted.

  18. Sum Rules and Moments of the Nucleon Spin Structure Functions

    SciTech Connect

    Jian-Ping Chen; Alexandre Deur; Zein-Eddine Meziani

    2005-08-01

    The nucleon has been used as a laboratory to investigate its own spin structure and Quantum Chromodynamics. New experimental data on nucleon spin structure at low to intermediate momentum transfers combined with existing high momentum transfer data offer a comprehensive picture of the transition region from the confinement regime of the theory to its asymptotic freedom regime. Insight for some aspects of the theory is gained by exploring lower moments of spin structure functions and their corresponding sum rules (i.e. the Gerasimov-Drell-Hearn, Bjorken and Burkhardt-Cottingham). These moments are expressed in terms of an operator product expansion using quark and gluon degrees of freedom at moderately large momentum transfers. The sum rules are verified to a good accuracy assuming that no singular behavior of the structure functions is present at very high excitation energies. The higher twist contributions have been examined through the moments evolution as the momentum transfer varies from higher to lower values. Furthermore, QCD-inspired low energy effective theories, which explicitly include chiral symmetry breaking, are tested at low momentum transfers. The validity of these theories is further examined as the momentum transfer increases to moderate values. It is found that chiral perturbation calculations agree reasonably well with the first moment of the spin structure function g{sub 1} at momentum transfer of 0.1 GeV{sup 2} but fail to reproduce the neutron data in the case of the generalized polarizability {delta}{sub LT}.

  19. Ultrafast optical demagnetization manipulates nanoscale spin structure in domain walls

    PubMed Central

    Pfau, B.; Schaffert, S.; Müller, L.; Gutt, C.; Al-Shemmary, A.; Büttner, F.; Delaunay, R.; Düsterer, S.; Flewett, S.; Frömter, R.; Geilhufe, J.; Guehrs, E.; Günther, C.M.; Hawaldar, R.; Hille, M.; Jaouen, N.; Kobs, A.; Li, K.; Mohanty, J.; Redlin, H.; Schlotter, W.F.; Stickler, D.; Treusch, R.; Vodungbo, B.; Kläui, M.; Oepen, H.P.; Lüning, J.; Grübel, G.; Eisebitt, S.

    2012-01-01

    During ultrafast demagnetization of a magnetically ordered solid, angular momentum has to be transferred between the spins, electrons, and phonons in the system on femto- and picosecond timescales. Although the intrinsic spin-transfer mechanisms are intensely debated, additional extrinsic mechanisms arising due to nanoscale heterogeneity have only recently entered the discussion. Here we use femtosecond X-ray pulses from a free-electron laser to study thin film samples with magnetic domain patterns. We observe an infrared-pump-induced change of the spin structure within the domain walls on the sub-picosecond timescale. This domain-topography-dependent contribution connects the intrinsic demagnetization process in each domain with spin-transport processes across the domain walls, demonstrating the importance of spin-dependent electron transport between differently magnetized regions as an ultrafast demagnetization channel. This pathway exists independent from structural inhomogeneities such as chemical interfaces, and gives rise to an ultrafast spatially varying response to optical pump pulses. PMID:23033076

  20. Comparison of the ferromagnetic Blume-Emery-Griffiths model and the AF spin-1 longitudinal Ising model at low temperature

    NASA Astrophysics Data System (ADS)

    Thomaz, M. T.; Corrêa Silva, E. V.

    2016-03-01

    We derive the exact Helmholtz free energy (HFE) of the standard and staggered one-dimensional Blume-Emery-Griffiths (BEG) model in the presence of an external longitudinal magnetic field. We discuss in detail the thermodynamic behavior of the ferromagnetic version of the model, which exhibits magnetic field-dependent plateaux in the z-component of its magnetization at low temperatures. We also study the behavior of its specific heat and entropy, both per site, at finite temperature. The degeneracy of the ground state, at T=0, along the lines that separate distinct phases in the phase diagram of the ferromagnetic BEG model is calculated, extending the study of the phase diagram of the spin-1 antiferromagnetic (AF) Ising model in S.M. de Souza and M.T. Thomaz, J. Magn. and Magn. Mater. 354 (2014) 205 [5]. We explore the implications of the equality of phase diagrams, at T=0, of the ferromagnetic BEG model with K/|J| = - 2 and of the spin-1 AF Ising model for D/|J| > 1/2.

  1. The spin structure function g1p of the proton and a test of the Bjorken sum rule

    NASA Astrophysics Data System (ADS)

    Adolph, C.; Akhunzyanov, R.; Alexeev, M. G.; Alexeev, G. D.; Amoroso, A.; Andrieux, V.; Anosov, V.; Austregesilo, A.; Azevedo, C.; Badełek, B.; Balestra, F.; Barth, J.; Baum, G.; 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.; Büchele, M.; Burtin, E.; Capozza, L.; 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.; Dziewiecki, M.; Efremov, A.; Eversheim, P. D.; Eyrich, W.; Ferrero, A.; Finger, M.; Finger, M.; Fischer, H.; Franco, C.; du Fresne von Hohenesche, N.; Friedrich, J. M.; Frolov, V.; Fuchey, E.; Gautheron, F.; Gavrichtchouk, O. P.; Gerassimov, S.; Giordano, F.; Gnesi, I.; Gorzellik, M.; Grabmüller, S.; Grasso, A.; Grosse-Perdekamp, M.; Grube, B.; Grussenmeyer, T.; Guskov, A.; Haas, F.; Hahne, D.; von Harrach, D.; Hashimoto, R.; Heinsius, F. H.; Herrmann, F.; Hinterberger, F.; Horikawa, N.; d'Hose, N.; -Yu Hsieh, C.; Huber, S.; Ishimoto, S.; Ivanov, A.; Ivanshin, Yu.; Iwata, T.; Jahn, R.; Jary, V.; 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.; Kremser, P.; Krinner, F.; Kroumchtein, Z. V.; Kuchinski, N.; 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.; 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.; Neyret, D.; Nikolaenko, V. I.; Novy, J.; Nowak, W.-D.; 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.; Platchkov, S.; Pochodzalla, J.; Polyakov, V. A.; Pretz, J.; Quaresma, M.; Quintans, C.; Ramos, S.; Regali, C.; Reicherz, G.; Riedl, C.; Rocco, E.; Rossiyskaya, N. S.; Ryabchikov, D. I.; Rychter, A.; Samoylenko, V. D.; Sandacz, A.; Santos, C.; Sarkar, S.; Savin, I. A.; Sbrizzai, G.; Schiavon, P.; Schmidt, K.; Schmieden, H.; Schönning, K.; Schopferer, S.; Selyunin, A.; Shevchenko, O. Yu.; Silva, L.; Sinha, L.; Sirtl, S.; Slunecka, M.; Sozzi, F.; Srnka, A.; Stolarski, M.; Sulc, M.; Suzuki, H.; Szabelski, A.; Szameitat, T.; Sznajder, P.; Takekawa, S.; ter Wolbeek, J.; Tessaro, S.; Tessarotto, F.; Thibaud, F.; Tosello, F.; Tskhay, V.; Uhl, S.; Veloso, J.; Virius, M.; Weisrock, T.; Wilfert, M.; Windmolders, R.; Zaremba, K.; Zavertyaev, M.; Zemlyanichkina, E.; Ziembicki, M.; Zink, A.

    2016-02-01

    New results for the double spin asymmetry A1p and the proton longitudinal spin structure function g1p are presented. They were obtained by the COMPASS Collaboration using polarised 200 GeV muons scattered off a longitudinally polarised NH3 target. The data were collected in 2011 and complement those recorded in 2007 at 160 GeV, in particular at lower values of x. They improve the statistical precision of g1p (x) by about a factor of two in the region x ≲ 0.02. A next-to-leading order QCD fit to the g1 world data is performed. It leads to a new determination of the quark spin contribution to the nucleon spin, ΔΣ, ranging from 0.26 to 0.36, and to a re-evaluation of the first moment of g1p. The uncertainty of ΔΣ is mostly due to the large uncertainty in the present determinations of the gluon helicity distribution. A new evaluation of the Bjorken sum rule based on the COMPASS results for the non-singlet structure function g1NS (x ,Q2) yields as ratio of the axial and vector coupling constants |gA /gV | = 1.22 ± 0.05 (stat.) ± 0.10 (syst.), which validates the sum rule to an accuracy of about 9%.

  2. Spin Structure Moments of the Proton and Deuteron

    SciTech Connect

    Slifer, Karl; Rondon-Aramayo, Oscar; Aghalaryan, Aram; Ahmidouch, Abdellah; Asaturyan, Razmik; Bloch, Frederic; Boeglin, Werner; Bosted, Peter; Carasco, Cedric; Carlini, Roger; Cha, Jinseok; Chen, Jian-Ping; Christy, Michael; Cole, Leon; Coman, Luminita; Crabb, Donald; Danagoulian, Samuel; Day, Donal; Dunne, James; Elaasar, Mostafa; Ent, Rolf; Fenker, Howard; Frlez, Emil; Gaskell, David; Gan, Liping; Gomez, Javier; Hu, Bitao; Jourdan, Juerg; Jones, Mark; Keith, Christopher; Keppel, Cynthia; Khandaker, Mahbubul; Klein, Andreas; Kramer, Laird; Liang, Yongguang; Lichtenstadt, Jechiel; Lindgren, Richard; Mack, David; McKee, Paul; McNulty, Dustin; Meekins, David; Mkrtchyan, Hamlet; Nasseripour, Rakhsha; Niculescu, Maria-Ioana; Normand, Kristoff; Norum, Blaine; Pocanic, Dinko; Prok, Yelena; Raue, Brian; Reinhold, Joerg; Roche, Julie; Rohe, Daniela; Savvinov, Nikolai; Sawatzky, Bradley; Seely, Mikell; Sick, Ingo; Smith, C.; Smith, G.; Stepanyan, Samuel; Tang, Liguang; Tajima, Shigeyuki; Testa, Giuseppe; Vulcan, William; Wang, Kebin; Warren, G.; Wesselmann, Frank; Wood, Stephen; Yan, Chen; Yuan, Lulin; Yun, Junho; Zeier, Markus; Guo Zhu, Hong

    2009-01-01

    Moments of the spin structure functions g1 and g2 of the proton and deuteron have been measured in the resonance region at intermediate four momentum transfer. We perform a Nachtmann moment analysis of this data, along with isovector and isoscalar combinations, in order to rigorously account for target mass effects. This analysis provides the first definitive evidence for dynamic higher twists.

  3. Spin transport in lateral structures with semiconducting channel

    NASA Astrophysics Data System (ADS)

    Zainuddin, Abu Naser

    Spintronics is an emerging field of electronics with the potential to be used in future integrated circuits. Spintronic devices are already making their mark in storage technologies in recent times and there are proposals for using spintronic effects in logic technologies as well. So far, major improvement in spintronic effects, for example, the `spin-valve' effect, is being achieved in metals or insulators as channel materials. But not much progress is made in semiconductors owing to the difficulty in injecting spins into them, which has only very recently been overcome with the combined efforts of many research groups around the world. The key motivations for semiconductor spintronics are their ease in integration with the existing semiconductor technology along with the gate controllability. At present semiconductor based spintronic devices are mostly lateral and are showing a very poor performance compared to their metal or insulator based vertical counterparts. The objective of this thesis is to analyze these devices based on spin-transport models and simulations. At first a lateral spin-valve device is modeled with the spin-diffusion equation based semiclassical approach. Identifying the important issues regarding the device performance, a compact circuit equivalent model is presented which would help to improve the device design. It is found that the regions outside the current path also have a significant influence on the device performance under certain conditions, which is ordinarily neglected when only charge transport is considered. Next, a modified spin-valve structure is studied where the spin signal is controlled with a gate in between the injecting and detecting contacts. The gate is used to modulate the rashba spin-orbit coupling of the channel which, in turn, modulates the spin-valve signal. The idea of gate controlled spin manipulation was originally proposed by Datta and Das back in 1990 and is called 'Datta-Das' effect. In this thesis, we have

  4. Structural disorder versus spin canting in monodisperse maghemite nanocrystals

    SciTech Connect

    Kubickova, S.; Vejpravova, J.; Niznansky, D.; Morales Herrero, M. P.

    2014-06-02

    Monodisperse maghemite nanoparticles with diameter ranging from 7 to 20 nm were examined by the In-field Mössbauer Spectroscopy (IFMS) in varying external magnetic field up to 6 T. Surprisingly, the small-sized particles (7 nm) exhibit nearly no spin canting in contrast to the larger particles with lower surface-to-volume ratio. We demonstrate that the observed phenomenon is originated by lower relative crystallinity of the larger particles with different internal structure. Hence, the persistence of the 2nd and 5th absorption lines in the IFMS cannot be unambiguously assigned to the surface spins.

  5. Structural disorder versus spin canting in monodisperse maghemite nanocrystals

    NASA Astrophysics Data System (ADS)

    Kubickova, S.; Niznansky, D.; Morales Herrero, M. P.; Salas, G.; Vejpravova, J.

    2014-06-01

    Monodisperse maghemite nanoparticles with diameter ranging from 7 to 20 nm were examined by the In-field Mössbauer Spectroscopy (IFMS) in varying external magnetic field up to 6 T. Surprisingly, the small-sized particles (7 nm) exhibit nearly no spin canting in contrast to the larger particles with lower surface-to-volume ratio. We demonstrate that the observed phenomenon is originated by lower relative crystallinity of the larger particles with different internal structure. Hence, the persistence of the 2nd and 5th absorption lines in the IFMS cannot be unambiguously assigned to the surface spins.

  6. Longitudinal Factor Structure of General Self-Concept and Locus of Control among High School Students

    ERIC Educational Resources Information Center

    Wang, Ze; Su, Ihui

    2013-01-01

    This study examined the longitudinal factor structure of general self-concept and locus of control among high school students over a 4-year period, with data from the National Educational Longitudinal Study of 1988. Measurement invariance was tested over time and across gender and ethnic groups; second-order piecewise latent growth models were…

  7. Geometrical structure and spin order of Gd13 cluster

    NASA Astrophysics Data System (ADS)

    Yuan, H. K.; Chen, H.; Kuang, A. L.; Wu, B.

    2011-09-01

    The spin-polarized generalized gradient approximation to the density-functional theory has been used to determine the lowest energy structure, electronic structure, and magnetic property of Gd13 cluster. Our results show that the ionic bonding is combined with the covalent characteristics in stabilizing the Gd cluster. The ferrimagnetic icosahedron is found to be the lowest energy configuration, in which the centered Gd atom couples antiferromagnetically with the rest Gd atoms surrounding it. No spin non-collinear evidence has been detected in our calculations. It is identified that the local magnetic moments of Gd atom are about 8 μB regardless of geometrical structure. Finally, the comprehensive electronic structure analyses show that the indirect long-range magnetic coupling between the polarized 4f is mediated by the polarization of 5d, 6s, and 6p conduction electrons, which is the typical Ruderman-Kittel-Kasuya-Yosida interactions.

  8. Prospects for HERMES-spin structure studies at HERA

    SciTech Connect

    Jackson, H.E.

    1994-12-31

    HERMES (HERA Measurement of Spin), is a second generation experiment to study the spin structure of the nucleon by using polarized internal gas targets in the HERA 35-GeV electron storage ring. Scattered electrons and coincident hadrons will be detected in an open geometry spectrometer which will include particle identification. Measurements are planned for each of the inclusive structure functions, g{sub 1},(x), g{sub 2}(x), b{sub 1}(x) and A(x), as well as the study of semi-inclusive pion and kaon asymmetries. Targets of hydrogen, deuterium and {sup 3}He will be studied. The accuracy of data for the inclusive structure functions will equal or exceed that of current experiments. The semi-inclusive asymmetries will provide a unique and sensitive probe of the flavor dependence of quark helicity distributions and properties of the quark sea. Monte Carlo simulations of HERMES data for experiment asymmetries and polarized structure functions are discussed.

  9. Spin Hall switching of the magnetization in Ta/TbFeCo structures with bulk perpendicular anisotropy

    SciTech Connect

    Zhao, Zhengyang; Jamali, Mahdi; Smith, Angeline K.; Wang, Jian-Ping

    2015-03-30

    Spin-orbit torques are studied in Ta/TbFeCo/MgO patterned structures, where the ferrimagnetic material TbFeCo provides a strong bulk perpendicular magnetic anisotropy (bulk-PMA) independent of the interfaces. The current-induced magnetization switching in TbFeCo is investigated in the presence of a perpendicular, longitudinal, or transverse field. An unexpected partial-switching phenomenon is observed in the presence of a transverse field unique to our bulk-PMA material. It is found that the anti-damping torque related with spin Hall effect is very strong, and a spin Hall angle is determined to be 0.12. The field-like torque related with Rashba effect is unobservable, suggesting that the interface play a significant role in Rashba-like torque.

  10. The Spin Structure of 3He and the Neutron at Low Q^2: A Measurement of the Generalized GDH Integrand

    SciTech Connect

    Sulkosky, Vincent

    2007-08-01

    Since the 1980's, the study of nucleon (proton or neutron) spin structure has been an active field both experimentally and theoretically. One of the primary goals of this work is to test our understanding of Quantum Chromodynamics (QCD), the fundamental theory of the strong interaction. In the high energy region of asymptotically free quarks, QCD has been verified. However, verifiable predictions in the low energy region are harder to obtain due to the complex interactions between the nucleon's constituents: quarks and gluons. In the non-pertubative regime, low-energy effective field theories such as chiral perturbation theory provide predictions for the spin structure functions in the form of sum rules. Spin-dependent sum rules such as the Gerasimov-Drell-Hearn (GDH) sum rule are important tools available to study nucleon spin structure. Originally derived for real photon absorption, the Gerasimov-Drell-Hearn (GDH) sum rule was first extended for virtual photon absorption in 1989. The extension of the sum rule provides a unique relation, valid at any momentum transfer ($Q^{2}$), that can be used to study the nucleon spin structure and make comparisons between theoretical predictions and experimental data. Experiment E97-110 was performed at the Thomas Jefferson National Accelerator Facility (Jefferson Lab) to examine the spin structure of the neutron and $^{3}$He. The Jefferson Lab longitudinally-polarized electron beam with incident energies between 1.1 and 4.4 GeV was scattered from a longitudinally or transversely polarized $^{3}$He gas target in the Hall A end station. Asymmetries and polarized cross-section differences were measured in the quasielastic and resonance regions to extract the spin structure functions $g_{1}(x,Q^{2})$ and $g_{2}(x,Q^{2})$ at low momentum transfers (0.02 $< Q^{2} <$ 0.3 GeV$^{2}$). The goal of the experiment was to perform a precise measurement of the $Q^{2}$ dependence of the extended GDH integral and of the moments of the neutron

  11. Neutron Spin Structure Measurements in JLab Hall A

    SciTech Connect

    J.P. Chen

    2004-09-01

    Recent progress from Jefferson Lab has significantly improved our understanding of the nucleon spin structure in the high-x region. Results from two experiments in Hall A are presented. The first experiment is a precision measurement of the neutron spin asymmetry, A{sub 1}{sup n}, in the high-x (valence quark) region. The results show for the first time that A{sub 1}{sup n} becomes positive at large x, strongly breaking SU(6) (spin-flavor) symmetry. The data trend is in good agreement with SU(6)-breaking valence quark models and with the fits to the previous world data. Combining the A{sub 1}{sup n} results with the world A{sub 1}{sup n} data, the up and down quark spin distributions in the nucleon were extracted. The results showed that for the proton the valence down quark spin is in the opposite direction from that of the proton, in disagreement with predictions of leading-order perturbative QCD models, which neglect quark orbital angular momentum.

  12. Nuclear spins and moments: Fundamental structural information

    SciTech Connect

    Semmes, P.B.

    1991-12-31

    Predictions for the low energy structure of well deformed odd-A Pm and Sm nuclei in the A {approx} 130 region are given, based on the particle-rotor model. Distinctive magnetic dipole properties (static moments and transition rates) are expected for certain Nilsson configurations, and comparisons to recent data are made for {sup 133}Pm, {sup 135}Sm and {sup 133}Sm.

  13. Nuclear spins and moments: Fundamental structural information

    SciTech Connect

    Semmes, P.B.

    1991-01-01

    Predictions for the low energy structure of well deformed odd-A Pm and Sm nuclei in the A {approx} 130 region are given, based on the particle-rotor model. Distinctive magnetic dipole properties (static moments and transition rates) are expected for certain Nilsson configurations, and comparisons to recent data are made for {sup 133}Pm, {sup 135}Sm and {sup 133}Sm.

  14. Nanoscale control of low-dimensional spin structures in manganites

    NASA Astrophysics Data System (ADS)

    Jing, Wang; Iftikhar, Ahmed Malik; Renrong, Liang; Wen, Huang; Renkui, Zheng; Jinxing, Zhang

    2016-06-01

    Due to the upcoming demands of next-generation electronic/magnetoelectronic devices with low-energy consumption, emerging correlated materials (such as superconductors, topological insulators and manganites) are one of the highly promising candidates for the applications. For the past decades, manganites have attracted great interest due to the colossal magnetoresistance effect, charge-spin-orbital ordering, and electronic phase separation. However, the incapable of deterministic control of those emerging low-dimensional spin structures at ambient condition restrict their possible applications. Therefore, the understanding and control of the dynamic behaviors of spin order parameters at nanoscale in manganites under external stimuli with low energy consumption, especially at room temperature is highly desired. In this review, we collected recent major progresses of nanoscale control of spin structures in manganites at low dimension, especially focusing on the control of their phase boundaries, domain walls as well as the topological spin structures (e.g., skyrmions). In addition, capacitor-based prototype spintronic devices are proposed by taking advantage of the above control methods in manganites. This capacitor-based structure may provide a new platform for the design of future spintronic devices with low-energy consumption. Project supported by the National Basic Research Program of China (Grant No. 2014CB920902), the National Natural Science Foundation of China (Grant Nos. 61306105 and 51572278), the Information Science and Technology (TNList) Cross-discipline Foundation from Tsinghua National Laboratory, China and the Fund from the State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China.

  15. Robust longitudinal spin-Seebeck effect in Bi-YIG thin films

    NASA Astrophysics Data System (ADS)

    Siegel, Gene; Prestgard, Megan Campbell; Teng, Shiang; Tiwari, Ashutosh

    2014-03-01

    In recent years, the coupling of magnetic insulators (bismuth-doped yttrium iron garnet, Bi-YIG) with platinum has garnered significant interest in spintronics research due to applicability as spin-current-driven thermoelectric coatings. These coatings bridge the gap between spintronics technologies and thermoelectric materials, providing a novel means of transforming waste heat into electricity. However, there remain questions regarding the origins of the spin-Seebeck effect (SSE) as well as claims that observed effects are a manifestation of magnetic proximity effects, which would induce magnetic behavior in platinum. Herewith we provide support that the voltages observed in the Bi-YIG/Pt films are purely SSE voltages. We reaffirm claims that magnon transport theory provides an ample basis for explaining SSE behavior. Finally, we illustrate the advantages of pulsed-laser deposition, as these Bi-YIG films possess large SSE voltages (even in absence of an external magnetic field), as much as twice those of films fabricated via solution-based methods.

  16. Viewing spin structures with soft x-ray microscopy

    SciTech Connect

    Fischer, Peter

    2010-06-01

    The spin of the electron and its associated magnetic moment marks the basic unit for magnetic properties of matter. Magnetism, in particular ferromagnetism and antiferromagnetism is described by a collective order of these spins, where the interaction between individual spins reflects a competition between exchange, anisotropy and dipolar energy terms. As a result the energetically favored ground state of a ferromagnetic system is a rather complex spin configuration, the magnetic domain structure. Magnetism is one of the eldest scientific phenomena, yet it is one of the most powerful and versatile utilized physical effects in modern technologies, such as in magnetic storage and sensor devices. To achieve highest storage density, the relevant length scales, such as the bit size in disk drives is now approaching the nanoscale and as such further developments have to deal with nanoscience phenomena. Advanced characterization tools are required to fully understand the underlying physical principles. Magnetic microscopes using polarized soft X-rays offer a close-up view into magnetism with unique features, these include elemental sensitivity due to X-ray magnetic dichroism effects as contrast mechanism, high spatial resolution provided by state-of-the-art X-ray optics and fast time resolution limited by the inherent time structure of current X-ray sources, which will be overcome with the introduction of ultrafast and high brilliant X-ray sources.

  17. Structural approaches to spin glasses and optimization problems

    NASA Astrophysics Data System (ADS)

    de Sanctis, Luca

    We introduce the concept of Random Multi-Overlap Structure (RaMOSt) as a generalization of the one introduced by M. Aizenman et al. for non-diluted spin glasses. We use this concept to find generalized bounds for the free energy of the Viana-Bray model of diluted spin glasses and to formulate and prove the Extended Variational Principle that implicitly provides the free energy of the model. Then we exhibit a theorem for the limiting RaMOSt, analogous to the one found by F. Guerra for the Sherrington-Kirkpatrick model, that describes some stability properties of the model. We also show how our technique can be used to prove the existence of the thermodynamic limit of the free energy. We then propose an ultrametric breaking of replica symmetry for diluted spin glasses in the framework of Random Multi-Overlap Structures (RaMOSt). Such a proposal is closer to the Parisi theory for non-diluted spin glasses than the theory based on the iterative approach. Our approach allows to formulate an ansatz in which the Broken Replica Symmetry trial function depends on a set of numbers, over which one has to take the infimum (as opposed to a nested chain of probabilty distributions). Our scheme suggests that the order parameter is determined by the probability distribution of the multi-overlap in a similar sense as in the non-diluted case, and it is not necessarily a functional. Such results are then extended to the K-SAT and p-XOR-SAT optimization problems, and to the spherical mean field spin glass. The ultrametric structure exhibits a factorization property similar to the one of the optimal structures for the Viana-Bray model. The present work paves the way to a revisited Parisi theory for diluted spin systems. Moreover, it emphasizes some structural analogies among different models, which also seem to be plausible for models that still escape good mathematical control. This structural analysis seems quite promising both mathematically and physically.

  18. Anatomy of a Spin: The Information-Theoretic Structure of Classical Spin Systems

    NASA Astrophysics Data System (ADS)

    James, Ryan; Vijayaraghavan, Vikram; Crutchfield, James

    Collective organization in matter plays a significant role in its expressed physical properties. Typically, it is detected via an order parameter, appropriately defined for a given system's observed emergent patterns. Recent developments in information theory suggest how to quantify collective organization in a system- and phenomenon-agnostic way: decompose the system's thermodynamic entropy density into a localized entropy, that solely contained in the dynamics at a single location, and a bound entropy, that stored in space as domains, clusters, excitations, or other emergent structures. We compute this decomposition and related quantities explicitly for the nearest-neighbor Ising model on the 1D chain, the Bethe lattice with coordination number k = 3, and the 2D square lattice, illustrating its generality and the functional insights it gives near and away from phase transitions. In particular, we consider the roles that different spin motifs play (cluster bulk, cluster edges, and the like) and how these affect the dependencies between spins.

  19. Quark-Hadron Duality in Neutron (3He) Spin Structure

    SciTech Connect

    Solvignon, Patricia; Liyanage, Nilanga; Chen, Jian-Ping; Choi, Seonho; Aniol, Konrad; Averett, Todd; Boeglin, Werner; Camsonne, Alexandre; Cates, Gordon; Chang, C.; Chang, C.C.; Chang, C.; Chang, C.C.; Chudakov, Eugene; Craver, Brandon; Cusanno, Francesco; Deur, Alexandre; Dutta, Dipangkar; Ent, Rolf; Feuerbach, Robert; Frullani, Salvatore; Gao, Haiyan; Garibaldi, Franco; Gilman, Ronald; Glashausser, Charles; Gorbenko, Viktor; Hansen, Jens-Ole; Higinbotham, Douglas; Ibrahim, Hassan; Jiang, Xiaodong; Jones, Mark; Kelleher, Aidan; Kelly, J.; Keppel, Cynthia; Kim, Wooyoung; Korsch, Wolfgang; Kramer, Kevin; Kumbartzki, Gerfried; LeRose, John; Lindgren, Richard; Ma, Bin; Margaziotis, Demetrius; Markowitz, Pete; McCormick, Kathy; Meziani, Zein-Eddine; Michaels, Robert; Moffit, Bryan; Monaghan, Peter; Munoz-Camacho, Carlos; Paschke, Kent; Reitz, Bodo; Saha, Arunava; Sheyor, Ran; Singh, Jaideep; Slifer, Karl; Sulkosky, Vince; Sulkosky, Vincent; Sulkosky, Vince; Sulkosky, Vincent; Tobias, William; Urciuoli, Guido; Wang, Kebin; Wijesooriya, Krishni; Wojtsekhowski, Bogdan; Woo, Seungtae; Yang, Jae-Choon; Zheng, Xiaochao; Zhu, Lingyan

    2008-10-01

    We present experimental results of the first high-precision test of quark-hadron duality in the spin-structure function g_1 of the neutron and $^3$He using a polarized 3He target in the four-momentum-transfer-squared range from 0.7 to 4.0 (GeV/c)^2. Global duality is observed for the spin-structure function g_1 down to at least Q^2 = 1.8 (GeV/c)^2 in both targets. We have also formed the photon-nucleon asymmetry A_1 in the resonance region for 3He and found no strong Q^2-dependence above 2.2 (GeV/c)^2.

  20. Spin Orbit Induced Electronic Structure and Magnetotransport in WTe2

    NASA Astrophysics Data System (ADS)

    Singh, David J.; Pan, Minghu; Yan, Jiaqiang; Yang, Biao; Zang, Yunyi; Zhang, Junjie; He, Ke; Wu, Menghao; Zhao, Yanfei; Mandrus, David; Wang, Jian; Xue, Qikun; Chi, Lifeng; Li, Qing

    We report electronic structure studies of WTe2, which shows an XMR behavior and is non-centrosymmetric. We find a spin-orbit split semimetallic band structure with a different Fermi surface topology than that initially reported, including Rashba split bands with Fermi surface around the zone center. The metallic properties are not one dimensional and are best described in terms of an anisotropic 3D metal with compensating low carrier density Fermi surfaces. The spin texture and transport is discussed as the origin of the XMR effect and in particular is consistent with the geometry in which the XMR effect is observed and its angle dependence. Work supported by DOE through the Computational Synthesis of Materials Software Project.

  1. Spin structure functions: Proton / deuteron measurements in the resonance region

    SciTech Connect

    Mark Jones; RSS Collaboration

    2006-02-01

    The RSS experiment ran in Hall C at Jefferson Lab and measured the proton and deuteron beam-target asymmetries for parallel and perpendicular target fields over a W range from pion threshold to 1.9 GeV at Q{sup 2} {approx} 1.3 GeV{sup 2}. Preliminary results for the proton spin structure functions g{sub 1} and g{sub 2} are presented.

  2. Precision Measurement of the Proton and Deuteron Spin Structure Functions g2

    SciTech Connect

    Rock, Stephen E.

    2003-02-27

    We measured the spin structure functions g{sub 2}{sup p} and g{sub 2}{sup d} in the range 0.02 {le} x {le} 0.8 and 0.7 {le} Q{sup 2} {le} 20 GeV{sup 2} by scattering 29.1 and 32.3 GeV longitudinally polarized electrons from transversely polarized NH{sub 3} and {sup 6}LiD targets. g{sub 2} approximately follows the twist-2 Wandzura-Wilczek calculation. The twist-3 reduced matrix elements d{sub 2}{sup p} and d{sub 2}{sup m} are less than two standard deviations from zero. The data are inconsistent with the Burkhardt-Cottingham sum rule if there is no pathological behavior as x {yields} 0. The Efremov-Leader-Teryaev integral is consistent with zero.

  3. Eigenstate-Assisted Longitudinal Quantum State Transfer and Qubit Storage in Photonic and Spin Lattices

    NASA Astrophysics Data System (ADS)

    Perez-Leija, Armando; Grafe, Markus; Heilmann, Rene; Keil, Robert; Stutzer, Simon; Weimann, Steffen; Christodoulides, Demetrios N.; Szameit, Alexander

    2014-05-01

    Coherent transport of quantum information between distant nodes plays a role of paramount importance for developing fair quantum computing technologies. In that vein, in this contribution we propose a novel photonic lattice system allowing the perfect transmission of photon encoded quantum information. The basic idea is to use the stationary nature of the associated eigenstates in order to transfer quantum states over long distances with unit fidelity. The proposed system consists of an array of evanescently coupled waveguides obeying a parabolic law distribution for the coupling strength between neighboring elements. In such an optical system, the eigenstates are readily excited provided single sites are fed with single photons. After the eigenstates have been excited, they propagate for very long distances without any distortion. Once the eigenstate has reached the desired distance, it is transformed into a single-site state simetrically residing on the oposite site of the array, performing so a perfect transfer of the initial state. Using these same principles we demonstrated the possibility of storage qubit in spin chains by exploiting the intrinsic time-invariance of the system eigenstates.

  4. Longitudinal spin transfer to {lambda} and {lambda} hyperons in polarized proton-proton collisions at {radical}(s)=200 GeV

    SciTech Connect

    Abelev, B. I.; Barannikova, O.; Betts, R. R.; Garcia-Solis, E. J.; Hofman, D. J.; Hollis, R. S.; Iordanova, A.; Kauder, K.; Suarez, M. C.; Aggarwal, M. M.; Bhati, A. K.; Kumar, L.; Pruthi, N. K.; Ahammed, Z.; Chattopadhyay, S.; Dutta Mazumdar, M. R.; Ganti, M. S.; Ghosh, P.; Mohanty, B.; Nayak, T. K.

    2009-12-01

    The longitudinal spin transfer, D{sub LL}, from high energy polarized protons to {lambda} and {lambda} hyperons has been measured for the first time in proton-proton collisions at {radical}(s)=200 GeV with the STAR detector at the Relativistic Heavy Ion Collider. The measurements cover pseudorapidity, {eta}, in the range |{eta}|<1.2 and transverse momenta, p{sub T}, up to 4 GeV/c. The longitudinal spin transfer is found to be D{sub LL}=-0.03{+-}0.13(stat){+-}0.04(syst) for inclusive {lambda} and D{sub LL}=-0.12{+-}0.08(stat){+-}0.03(syst) for inclusive {lambda} hyperons with <{eta}>=0.5 and =3.7 GeV/c. The dependence on {eta} and p{sub T} is presented.

  5. Longitudinal Spin Transfer to Lambda and Lambda bar Hyperons in Polarized Proton-Proton Collisions at sqrt s = 200 GeV

    SciTech Connect

    STAR Collaboration; Abelev, Betty

    2010-07-05

    The longitudinal spin transfer, D{sub LL}, from high energy polarized protons to {Lambda} and {bar {Lambda}} hypersons has been measured for the first time in proton-proton collisions at {radical}s = 200 GeV with the STAR detector at RHIC. The measurements cover pseudorapidity, {eta}, in the range |{eta}| < 1.2 and transverse momenta, p{sub T}, up to 4 GeV/c. The longitudinal spin transfer is found to be D{sub LL} = -0.03{+-}0.13(stat){+-}0.04(syst) for inclusive {Lambda} and D{sub LL} = -0.12{+-}0.08(stat){+-}0.03(syst) for inclusive {bar {Lambda}} hyperons with <{eta}> = 0.5 and = 3.7 GeV/c. The dependence on {eta} and p{sub T} is presented.

  6. Longitudinal Spin Transfer of LAMBDA and LAMBDA-bar Hyperons in Polarized Proton-Proton Collisions at sq root(s) = 200 GeV

    SciTech Connect

    Sichtermann, Ernst

    2009-08-04

    The longitudinal spin transfer D{sub LL} of LAMBDA and LAMBDA-bar hyperons produced with large transverse momenta P{sub T} in polarized proton-proton collisions is sensitive to the helicity distribution functions of strange quarks and anti-quarks, and to polarized fragmentation functions. This contribution reports a measurement of the longitudinal spin transfer D{sub LL} in the inclusive production of LAMBDA and LAMBDA-bar hyperons at central rapidities in polarized proton-proton collisions at a center of mass energy of sq root(s) = 200 GeV. The data were collected with the STAR experiment at RHIC and correspond to a approx =3 pb{sup -1} luminosity and a approx =50% beam polarization.

  7. Longitudinal spin transfer to {Lambda} and {bar Lambda} hyperons in polarized proton-proton collisions at {radical}{ovr s} = 200 GeV.

    SciTech Connect

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Alakhverdyants, A. V.; Anderson, B. D.; Bridgeman, A.; Krueger, K.; Spinka, H. M.; Underwood, D. G.; STAR Collaboration

    2009-01-01

    The longitudinal spin transfer, D{sub LL}, from high energy polarized protons to {Lambda} and {bar {Lambda}} hyperons has been measured for the first time in proton-proton collisions at {radical}s = 200 GeV with the STAR detector at the Relativistic Heavy Ion Collider. The measurements cover pseudorapidity, {eta}, in the range |{eta}| < 1.2 and transverse momenta, p{sub T}, up to 4 GeV/c. The longitudinal spin transfer is found to be D{sub LL} = -0.03 {+-} 0.13(stat) {+-} 0.04(syst) for inclusive {Lambda} and D{sub LL} = -0.12 {+-} 0.08(stat) {+-} 0.03(syst) for inclusive {bar {Lambda}} hyperons with {eta} = 0.5 and p{sub T} =3.7 GeV/c. The dependence on {eta} and p{sub T} is presented.

  8. Longitudinal double-spin asymmetry and cross section for inclusive neutral pion production at midrapidity in polarized proton collisions at s=200GeV

    NASA Astrophysics Data System (ADS)

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Alakhverdyants, A. V.; Anderson, B. D.; Arkhipkin, D.; Averichev, G. S.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baumgart, S.; Beavis, D. R.; Bellwied, R.; Benedosso, F.; Betancourt, M. J.; Betts, R. R.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Biritz, B.; Bland, L. C.; Bonner, B. E.; Bouchet, J.; Braidot, E.; Brandin, A. V.; Bridgeman, A.; Bruna, E.; Bueltmann, S.; Bunzarov, I.; Burton, T. P.; Cai, X. Z.; Caines, H.; Sánchez, M. Calderón De La Barca; Catu, O.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, J. Y.; Cheng, J.; Cherney, M.; Chikanian, A.; Choi, K. E.; Christie, W.; Chung, P.; Clarke, R. F.; Codrington, M. J. M.; Corliss, R.; Cramer, J. G.; Crawford, H. J.; Das, D.; Dash, S.; Leyva, A. Davila; Silva, L. C. De; Debbe, R. R.; Dedovich, T. G.; Dephillips, M.; Derevschikov, A. A.; de Souza, R. Derradi; Didenko, L.; Djawotho, P.; Dogra, S. M.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Dunlop, J. C.; Mazumdar, M. R. Dutta; Efimov, L. G.; Elhalhuli, E.; Elnimr, M.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Eun, L.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Fersch, R. G.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Gagliardi, C. A.; Gangadharan, D. R.; Ganti, M. S.; Garcia-Solis, E. J.; Geromitsos, A.; Geurts, F.; Ghazikhanian, V.; Ghosh, P.; Gorbunov, Y. N.; Gordon, A.; Grebenyuk, O.; Grosnick, D.; Grube, B.; Guertin, S. M.; Gupta, A.; Gupta, N.; Guryn, W.; Haag, B.; Hallman, T. J.; Hamed, A.; Han, L.-X.; Harris, J. W.; Hays-Wehle, J. P.; Heinz, M.; Heppelmann, S.; Hirsch, A.; Hjort, E.; Hoffman, A. M.; Hoffmann, G. W.; Hofman, D. J.; Hollis, R. S.; Huang, H. Z.; Humanic, T. J.; Huo, L.; Igo, G.; Iordanova, A.; Jacobs, P.; Jacobs, W. W.; Jakl, P.; Jena, C.; Jin, F.; Jones, C. L.; Jones, P. G.; Joseph, J.; Judd, E. G.; Kabana, S.; Kajimoto, K.; Kang, K.; Kapitan, J.; Kauder, K.; Keane, D.; Kechechyan, A.; Kettler, D.; Kikola, D. P.; Kiryluk, J.; Kisiel, A.; Klein, S. R.; Knospe, A. G.; Kocoloski, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Kopytine, M.; Koralt, I.; Korsch, W.; Kotchenda, L.; Kouchpil, V.; Kravtsov, P.; Krueger, K.; Krus, M.; Kumar, L.; Kurnadi, P.; Lamont, M. A. C.; Landgraf, J. M.; Lapointe, S.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, C.-H.; Lee, J. H.; Leight, W.; Levine, M. J.; Li, C.; Li, L.; Li, N.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z.; Lin, G.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, J.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Love, W. A.; Lu, Y.; Ma, G. L.; Ma, Y. G.; Mahapatra, D. P.; Majka, R.; Mall, O. I.; Mangotra, L. K.; Manweiler, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; Matulenko, Yu. A.; McDonald, D.; McShane, T. S.; Meschanin, A.; Milner, R.; Minaev, N. G.; Mioduszewski, S.; Mischke, A.; Mitrovski, M. K.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Munhoz, M. G.; Nandi, B. K.; Nattrass, C.; Nayak, T. K.; Nelson, J. M.; Netrakanti, P. K.; Ng, M. J.; Nogach, L. V.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okada, H.; Okorokov, V.; Olson, D.; Pachr, M.; Page, B. S.; Pal, S. K.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Phatak, S. C.; Pile, P.; Planinic, M.; Ploskon, M. A.; Pluta, J.; Plyku, D.; Poljak, N.; Poskanzer, A. M.; Potukuchi, B. V. K. S.; Powell, C. B.; Prindle, D.; Pruneau, C.; Pruthi, N. K.; Pujahari, P. R.; Putschke, J.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Redwine, R.; Reed, R.; Rehberg, J. M.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Rose, A.; Roy, C.; Ruan, L.; Russcher, M. J.; Sahoo, R.; Sakai, S.; Sakrejda, I.; Sakuma, T.; Salur, S.; Sandweiss, J.; Sangaline, E.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Schuster, T. R.; Seele, J.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shahaliev, E.; Shao, M.; Sharma, M.; Shi, S. S.; Sichtermann, E. P.; Simon, F.; Singaraju, R. N.; Skoby, M. J.; Smirnov, N.; Sorensen, P.; Sowinski, J.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Staszak, D.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Suarez, M. C.; Subba, N. L.; Sumbera, M.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Symons, T. J. M.; de Toledo, A. Szanto; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarini, L. H.; Tarnowsky, T.; Thein, D.; Thomas, J. H.; Tian, J.; Timmins, A. R.; Timoshenko, S.; Tlusty, D.; Tokarev, M.; Trainor, T. A.; Tram, V. N.; Trentalange, S.; Tribble, R. E.; Tsai, O. D.; Ulery, J.; Ullrich, T.; Underwood, D. G.; van Buren, G.; van Nieuwenhuizen, G.; Vanfossen, J. A., Jr.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Videbaek, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Wada, M.; Walker, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, Q.; Wang, X.; Wang, X. L.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Whitten, C., Jr.; Wieman, H.; Wingfield, E.; Wissink, S. W.; Witt, R.; Wu, Y.; Xie, W.; Xu, N.; Xu, Q. H.; Xu, W.; Xu, Y.; Xu, Z.; Xue, L.; Yang, Y.; Yepes, P.; Yip, K.; Yoo, I.-K.; Yue, Q.; Zawisza, M.; Zbroszczyk, H.; Zhan, W.; Zhang, S.; Zhang, W. M.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, J.; Zhong, C.; Zhou, J.; Zhou, W.; Zhu, X.; Zhu, Y. H.; Zoulkarneev, R.; Zoulkarneeva, Y.

    2009-12-01

    We report a measurement of the longitudinal double-spin asymmetry ALL and the differential cross section for inclusive π0 production at midrapidity in polarized proton collisions at s=200GeV. The cross section was measured over a transverse momentum range of 1longitudinal double-spin asymmetry was measured in the range of 3.7

  9. Measurement of Inclusive Spin Structure Functions of the Deuteron with CLAS

    SciTech Connect

    J. Yun; CLAS Collaboration

    2002-12-01

    We report the results of a new measurement of spin structure functions of the deuteron in the region of moderate momentum transfer (Q{sup 2} = 0.27 -- 1.3 (GeV/c){sup 2}) and final hadronic state mass in the nucleon resonance region (W = 1.08 -- 2.0 GeV). We scattered a 2.5 GeV polarized continuous electron beam at Jefferson Lab off a dynamically polarized cryogenic solid state target ({sup 15}ND{sub 3}) and detected the scattered electrons with the CEBAF Large Acceptance Spectrometer (CLAS). From our data, we extract the longitudinal double spin asymmetry A{sub {parallel}} and the spin structure function g{sub 1}{sup d}. Our data are generally in reasonable agreement with existing data from SLAC where they overlap, and they represent a substantial improvement in statistical precision. We compare our results with expectations for resonance asymmetries and extrapolated deep inelastic scaling results. Finally, we evaluate the first moment of the structure function g{sub 1}{sup d} and study its approach to both the deep inelastic limit at large Q{sup 2} and to the Gerasimov-Drell-Hearn sum rule at the real photon limit (Q{sup 2}-0). We find that the first moment varies rapidly in the Q{sup 2} range of our experiment and crosses zero at Q{sup 2} between 0.5 and 0.8 (GeV/c){sup 2}, indicating the importance of the {Delta} resonance at these momentum transfers.

  10. High-spin structures in the 129Xe nucleus

    NASA Astrophysics Data System (ADS)

    Huang, Y.; Xiao, Z. G.; Zhu, S. J.; Qi, C.; Xu, Q.; Cheng, W. J.; Li, H. J.; Lyu, L. M.; Wang, R. S.; Yan, W. H.; Yi, H.; Zhang, Y.; Chen, Q. M.; He, C. Y.; Hu, S. P.; Li, C. B.; Li, H. W.; Luo, P. W.; Wu, X. G.; Wu, Y. H.; Zheng, Y.; Zhong, J.

    2016-06-01

    High-spin states in the 129Xe nucleus are studied with the reaction 124Sn(9Be,4 n ) at a beam energy of 36 MeV. The level scheme is extended significantly. For the positive-parity band, the α =+1 /2 and the α =-1 /2 signature components are combined to form a complete band structure based on the 3 /2+ state with spin and parity up to 21 /2+ . For the negative-parity band based on the 11 /2- state, the α =+1 /2 signature component is newly established and both the α =+1 /2 and the α =-1 /2 signature components also form a complete band structure up to the 35 /2- state. The positive- and negative-parity bands are proposed to originate from ν d3 /23 /2+[402 ] and ν h11 /211 /2-[505 ] Nilsson configurations, respectively. A backbending is observed in the negative-parity band, which originates from the alignments of two h11 /2 protons according to crank shell model calculations. Based on the total Routhian surface and quasiparticle triaxial rotor model calculations, the negative-parity band is interpreted as a triaxially deformed shape with γ ≈-30∘ , while the positive-parity band is associated with γ softness, in accordance with previous studies. In the high-spin states, three decoupled bands and one oblate band with γ ≈-60∘ are newly identified. The systematics and other characteristics of these bands are discussed.

  11. High-spin structure of {sup 102}Ru

    SciTech Connect

    Sohler, D.; Timar, J.; Molnar, J.; Dombradi, Zs.; Krasznahorkay, A.; Zolnai, L.; Rainovski, G.; Joshi, P.; Wadsworth, R.; Jenkins, D.G.; Raddon, P.M.; Simons, A.J.; Wilkinson, A.R.; Starosta, K.; Fossan, D.B.; Koike, T.; Vaman, C.; Algora, A.; Bednarczyk, P.; Curien, D.

    2005-06-01

    High-spin states in the nucleus {sup 102}Ru have been investigated via the {sup 96}Zr({sup 13}C,{alpha}3n) reaction at beam energies of 51 and 58 MeV, using the euroball IV {gamma}-ray spectrometer and the diamant charged particle array. Several new high-spin bands have been established. The ground-state band has been extended up to E{sub x}{approx}12 MeV with I{sup {pi}}=(26{sup +}); the previously published negative-parity bands have been extended up to E{sub x}{approx}11 and {approx} 9 MeV with I{sup {pi}}=(23{sup -}) and (20{sup -}), respectively. The deduced high-spin structure has been compared with Woods-Saxon total Routhian surface calculations and, on the basis of the measured Routhians, aligned angular momenta, and B(M1)/B(E2) ratios, {nu}h{sub 11/2}(g{sub 7/2},d{sub 5/2}) configurations are suggested for the negative-parity structures.

  12. Measuring spin-dependent structure functions at CEBAF

    SciTech Connect

    Schaefer, A.

    1994-04-01

    The author analyses whether CEBAF with a 10 GeV beam could contribute significantly to the understanding of spin-dependent deep-inelastic scattering as well as semi-inclusive reactions. The main advantage of CEBAF is the much better attainable statistics, its great disadvantage its comparably low energy, which limits the accessible x-range to about 0.15 to 0.7. Within these constraints CEBAF could provide (1) high precision data which would be very valuable to understand the Q{sup 2} dependence of the spin-dependent structure functions g{sub 1}(x) and G{sub 2}(x) and (2) the by far most precise determination of the third moments of g{sub 1}(x) and g{sub 2}(x) the latter of which the author argues to be related to a fundamental property of the nucleon.

  13. High-spin nuclear structure data on the Internet

    SciTech Connect

    Singh, B. |

    1997-12-31

    The study of nuclear structure at fast nuclear rotations, using fusion-evaporation reactions, started in the early sixties but since the experimental observation of superdeformation about a decade ago it has become one of the most pursued research topics in nuclear physics. Large gamma-ray detector arrays GAMMASPHERE, EUROGAM, and GASP were developed during the last few years and these continue to produce a wealth of new, information about the properties of nuclei at high spins, including superdeformation. It is considered vital to compile, evaluate and systematize published data on many thousands of levels and gamma rays and associated nuclear bands obtained in such studies and make these available to the research community in conveniently retrievable and modern formats. This talk will describe the numerical, bibliographic and other high-spin related databases that are already accessible via INTERNET. Present limitations and ways to improve the current status and display of such databases will also be discussed.

  14. Balancing Newtonian gravity and spin to create localized structures

    NASA Astrophysics Data System (ADS)

    Bush, Michael; Lindner, John

    2015-03-01

    Using geometry and Newtonian physics, we design localized structures that do not require electromagnetic or other forces to resist implosion or explosion. In two-dimensional Euclidean space, we find an equilibrium configuration of a rotating ring of massive dust whose inward gravity is the centripetal force that spins it. We find similar solutions in three-dimensional Euclidean and hyperbolic spaces, but only in the limit of vanishing mass. Finally, in three-dimensional Euclidean space, we generalize the two-dimensional result by finding an equilibrium configuration of a spherical shell of massive dust that supports itself against gravitational collapse by spinning isoclinically in four dimensions so its three-dimensional acceleration is everywhere inward. These Newtonian ``atoms'' illuminate classical physics and geometry.

  15. ac susceptibility of chosen chromium compounds with noncollinear spin structure

    NASA Astrophysics Data System (ADS)

    Juszczyk, S.; Gogołowicz, M.

    1993-11-01

    Results from the preliminary ac susceptibility χ ac( T) measurements at H( rms)=80 A/ m and ƒ=1 kHz on the chosen chromate Zn 1- xA xCr 2Se 4 with noncollinear spin structure for A=Cu and Ga {2}/{3} are presented. From the temperature position peak of the in-phase (real, χ') part of the complex susceptibility the transition temperatures from a magnetically ordered phase to a paramagnetic one have been determined. The out-of-phase (imaginary of absorptive, χ″) peak is discussed in terms of different spin-lattice relaxation processes causing a dissipation of energy. A proposal that in both the real and imaginary part of the ac susceptibility a significant role can be played by a skin size effect is also presented.

  16. Total Longitudinal Moment Calculation and Reliability Analysis of Yacht Structures

    NASA Astrophysics Data System (ADS)

    Zhi, Wenzheng; Lin, Shaofen

    In order to check the reliability of the yacht in FRP (Fiber Reinforce Plastic) materials, in this paper, the vertical force and the calculation method of the overall longitudinal bending moment on yacht was analyzed. Specially, this paper focuses on the impact of speed on the still water bending moment on yacht. Then considering the mechanical properties of the cap type stiffeners in composite materials, the ultimate bearing capacity of the yacht has been worked out, finally the reliability of the yacht was calculated with using response surface methodology. The result can be used in yacht design and yacht driving.

  17. E8 spectrum and the finite temperature spin dynamics in the transverse field Ising chain with a small longitudinal field

    NASA Astrophysics Data System (ADS)

    Wu, Jianda; Kormos, Marton; Si, Qimiao

    2013-03-01

    When the transverse field Ising chain at its quantum critical point is subjected to a small longitudinal field, the perturbed conformal field theory led to a field theory with an exotic E8 symmetry. Recent neutron scattering experiments have provided evidence for the lightest two particles in this E8 model in the quasi-1D Ising ferromagnet CoNb2O6. While the zero temperature dynamics of the model is well known, its finite-temperature counterpart has not yet been systematically studied. We study the low-frequency dynamical structure factor at finite temperatures using the form-factor method. We show that the dominant contribution to the dynamical structure factor comes from the scattering between two lightest particles, and discuss the implications of our results for the NMR relaxation rate.

  18. Detection of DC currents and resistance measurements in longitudinal spin Seebeck effect experiments on Pt/YIG and Pt/NFO

    NASA Astrophysics Data System (ADS)

    Meier, Daniel; Kuschel, Timo; Meyer, Sibylle; Goennenwein, Sebastian T. B.; Shen, Liming; Gupta, Arunava; Schmalhorst, Jan-Michael; Reiss, Günter

    2016-05-01

    In this work we investigated thin films of the ferrimagnetic insulators Y 3Fe5O12 and NiFe2O4 capped with thin Pt layers in terms of the longitudinal spin Seebeck effect (LSSE). The electric response detected in the Pt layer under an out-of-plane temperature gradient can be interpreted as a pure spin current converted into a charge current via the inverse spin Hall effect. Typically, the transverse voltage is the quantity investigated in LSSE measurements (in the range of μV). Here, we present the directly detected DC current (in the range of nA) as an alternative quantity. Furthermore, we investigate the resistance of the Pt layer in the LSSE configuration. We found an influence of the test current on the resistance. The typical shape of the LSSE curve varies for increasing test currents.

  19. Geometric structure, electronic structure, and spin transition of several Fe{sup II} spin-crossover molecules

    SciTech Connect

    Tuan, Nguyen Anh

    2012-04-01

    We present a density functional study on the geometric structure, electronic structure, and spin transition of a series of Fe{sup II} spin-crossover (SCO) molecules, i.e., [Fe(abpt){sub 2}(NCS){sub 2}] (1), [Fe(abpt){sub 2}(NCSe){sub 2}] (2), and [Fe(dpbo)(HIm){sub 2}] (3) with dpbo diethyl(E,E)-2,2'-[1,2-phenylbis(iminomethylidyne)]bis[3-oxobutanoate](2-), N',O{sup 3},O{sup 3}', and abpt = 4-amino-3,5-bis(pyridin-2-yl)-1,2,4-triazole in order to explore more about the way to control SCO behavior of transition metal complexes. Our calculated results show that the spin transition of these Fe{sup II} molecules is accompanied with charge transfer between the Fe atom and ligands. This causes change in the electrostatic energy ({Delta}U) as well as the total electronic energy of SCO molecules. Moreover, our calculated results demonstrate an important contribution of the interionic interactions to {Delta}U, and there is the relation between {Delta}U and the thermal hysteresis behavior of SCO molecules. These results should be helpful for developing new SCO molecules.

  20. Longitudinal displacement in viscoelastic arteries: a novel fluid-structure interaction computational model, and experimental validation.

    PubMed

    Bukač, Martina; Čanić, Sunčica

    2013-04-01

    Recent in vivo studies, utilizing ultrasound contour and speckle tracking methods, have identified significant longitudinal displacements of the intima-media complex, and viscoelastic arterial wall properties over a cardiac cycle. Existing computational models that use thin structure approximations of arterial walls have so far been limited to models that capture only radial wall displacements. The purpose of this work is to present a simple fluid-struture interaction (FSI) model and a stable, partitioned numerical scheme, which capture both longitudinal and radial displacements, as well as viscoelastic arterial wall properties. To test the computational model, longitudinal displacement of the common carotid artery and of the stenosed coronary arteries were compared with experimental data found in literature, showing excellent agreement. We found that, unlike radial displacement, longitudinal displacement in stenotic lesions is highly dependent on the stenotic geometry. We also showed that longitudinal displacement in atherosclerotic arteries is smaller than in healthy arteries, which is in line with the recent in vivo measurements that associate plaque burden with reduced total longitudinal wall displacement. This work presents a first step in understanding the role of longitudinal displacement in physiology and pathophysiology of arterial wall mechanics using computer simulations. PMID:23458302

  1. Vortex Flipping in Superconductor-Ferromagnet Spin Valve Structures

    NASA Astrophysics Data System (ADS)

    Patino, Edgar J.; Aprili, Marco; Blamire, Mark; Maeno, Yoshiteru

    2014-03-01

    We report in plane magnetization measurements on Ni/Nb/Ni/CoO and Co/Nb/Co/CoO spin valve structures with one of the ferromagnetic layers pinned by an antiferromagnetic layer. In samples with Ni, below the superconducting transition Tc, our results show strong evidence of vortex flipping driven by the ferromagnets magnetization. This is a direct consequence of proximity effect that leads to vortex supercurrents leakage into the ferromagnets. Here the polarized electron spins are subject to vortices magnetic field occasioning vortex flipping. Such novel mechanism has been made possible for the first time by fabrication of the F/S/F/AF multilayered spin valves with a thin-enough S layer to barely confine vortices inside as well as thin-enough F layers to align and control the magnetization within the plane. When Co is used there is no observation of vortex flipping effect. This is attributed to Co shorter coherence length. Interestingly instead a reduction in pinning field of about 400 Oe is observed when the Nb layer is in superconducting state. This effect cannot be explained in terms of vortex fields. In view of these facts any explanation must be directly related to proximity effect and thus a remarkable phenomenon that deserves further investigation. Programa Nacional de Ciencias Basicas COLCIENCIAS (No. 120452128168).

  2. Interdependence of spin structure, anion height and electronic structure of BaFe2As2

    NASA Astrophysics Data System (ADS)

    Sen, Smritijit; Ghosh, Haranath

    2016-05-01

    Superconducting as well as other electronic properties of Fe-based superconductors are quite sensitive to the structural parameters specially, on anion height which is intimately related to zAs, the fractional z co-ordinate of As atom. Due to presence of strong magnetic fluctuation in these Fe-based superconductors, optimized structural parameters (lattice parameters a, b, c) including zAs using density functional theory (DFT) under generalized gradient approximation (GGA) does not match experimental values accurately. In this work, we show that the optimized value of zAs is strongly influenced by the spin structures in the orthorhombic phase of BaFe2As2 system. We take all possible spin structures for the orthorhombic BaFe2As2 system and then optimize zAs. Using these optimized structures we calculate electronic structures like density of states, band structures etc., for each spin configurations. From these studies we show that the electronic structure, orbital order which is responsible for structural as well as related to nematic transition, are significantly influenced by the spin structures.

  3. Free-Spinning, Longitudinal-Trim, and Tumbling Characteristics of a 1/20-Scale Model of the Consolidated Vultke MX-813 (Prototype of XP-92) Airplane as Determined in the Langley 20-Foot Free-Spinning Tunnel

    NASA Technical Reports Server (NTRS)

    Stone, Ralph W., Jr.; White, Richard P.

    1948-01-01

    An investigation has been conducted in the Langley 20-foot free-spinning tunnel to evaluate the spin, longitudinal-trim, and tumbling characteristics of a 1/20-scale model of the Consolidated Vultee MX-813 airplane. The effects of control position were determined for the model ballasted to represent the airplane in its design gross weight loading. The model, in general, would not spin but demonstrated a tendency to trim at very high stalled angles of attack. Static tests substantiated the dynamic tests as regards the trim characteristics. Movement of the elevator, however, from up to slightly down was effective in pitching the model from stalled to normal trim attitudes. The model would not tumble.

  4. Longitudinal structure of substorm injections at synchronous orbit

    SciTech Connect

    Arnoldy, R.L.; Moore, T.E.

    1983-08-01

    From multiple-spacecraft measurements it is shown that the synchronous orbit manifestation of a substorm, i.e., plasma injection and magnetic field reconfiguration to dipolar, has an onset which expands both eastward and westward from a relatively narrow sector near midnight. For low-to-moderate geomagnetic activity the earliest onset sector at synchronous orbit is about 3 hours wide, skewed toward the evening side of midnight. Using the extensive International Magnetospheric Study ground magnetometer network beneath the satellites, it is found that simultaneous westward motion of electrojet intensification is seen in the ground data over a large longitudinal range than the magnetospheric signatures. This might be explained in terms of distortion of the nightside magnetic field at synchronous orbit. Plasma that might be explained in terms of distortion of the nightside magnetic field at synchronous orbit. Plasma that has already been injected near midnight at synchronous altitude undergoes no further change as a result of the westward and eastward motion of the borders of the plasma. This suggest that the expansion does not represent new substorm activation. One can intepret these results in terms of an injection front wedge which makes hot plasma accessible to the inner magnetosphere and which spatially expands or propagates with time. The origin of plasma behind the front is not addressed. Detailed pitch angle data do, however, show that strong precipitation would be expected from the front for about the first 10 min after the front passes over an observer. Finally, as a result of longitudinal expansion of plasma injections from midnight toward evening or morning and the continuation or even enhancement of field inflation in the evening or morning sectors, growth and expansive phase substorm signatures can occur simultaneously.

  5. Causal Structure around Spinning 5-DIMENSIONAL Cosmic Strings

    NASA Astrophysics Data System (ADS)

    Slagter, Reinoud Jan

    2008-09-01

    We present a numerical solution of a stationary 5-dimensional spinning cosmic string in the Einstein-Yang-Mills (EYM) model, where the extra bulk coordinate ψ is periodic. It turns out that when gψψ approaches zero, i.e., a closed time-like curve (CTC) would appear, the solution becomes singular. We also investigated the geometrical structure of the static 5D cosmic string. Two opposite moving 5D strings could, in contrast with the 4D case, fulfil the Gott condition for CTC formation.

  6. Interplay between magnetic interactions in spin-valve structures

    NASA Astrophysics Data System (ADS)

    Rodríguez-Suárez, R. L.; Oliveira, A. B.; Rezende, S. M.; Azevedo, A.

    2006-04-01

    In this work we report on the experimental and theoretical investigations of the effects of various magnetic couplings existing in spin-valve structures. Magnetic interactions such as the exchange bias that occurs at the ferromagnetic/antiferromagnetic interface and the indirect coupling between ferromagnetic (FM) layers mediated by a nonmagnetic metal spacer as well as the interchange between both kinds of interactions were investigated. The unidirectional anisotropy that pins the magnetization of the pinned layer transmits to the free layer throughout the nonmagnetic spacer. Also, the resonance fields of the FM layers show an upward (downward) shift for an antiferromagnetic (ferromagnetic) bilinear coupling.

  7. Magnetic field-dependent spin structures of nanocrystalline holmium

    PubMed Central

    Szary, Philipp; Kaiser, Daniel; Bick, Jens-Peter; Lott, Dieter; Heinemann, André; Dewhurst, Charles; Birringer, Rainer; Michels, Andreas

    2016-01-01

    The results are reported of magnetic field-dependent neutron diffraction experiments on polycrystalline inert-gas condensed holmium with a nanometre crystallite size (D = 33 nm). At T = 50 K, no evidence is found for the existence of helifan(3/2) or helifan(2) structures for the nanocrystalline sample, in contrast with results reported in the literature for the single crystal. Instead, when the applied field H is increased, the helix pattern transforms progressively, most likely into a fan structure. It is the component of H which acts on the basal-plane spins of a given nanocrystallite that drives the disappearance of the helix; for nanocrystalline Ho, this field is about 1.3 T, and it is related to a characteristic kink in the virgin magnetization curve. For a coarse-grained Ho sample, concomitant with the destruction of the helix phase, the emergence of an unusual angular anisotropy (streak pattern) and the appearance of novel spin structures are observed. PMID:27047307

  8. Spin Diffusion Editing for Structural Fingerprints of Therapeutic Antibodies.

    PubMed

    Franks, Joshua; Glushka, John N; Jones, Michael T; Live, David H; Zou, Qin; Prestegard, James H

    2016-01-19

    The growing importance of biologics and biosimilars as therapeutic and diagnostic agents is giving rise to new demands for analytical methodology that can quickly and accurately assess the chemical and physical state of protein-based products. A particular challenge exists in physical characterization where the proper fold and extent of disorder of a protein is a major concern. The ability of NMR to reflect structural and dynamic properties of proteins is well recognized, but sensitivity limitations and high levels of interference from excipients in typical biologic formulations have prevented widespread applications to quality assessment. Here we demonstrate applicability of a simple one-dimensional proton NMR method that exploits enhanced spin diffusion among protons in well-structured areas of a protein. We show that it is possible to reduce excipient signals and allow focus on structural characteristics of the protein. Additional decomposition of the resulting spectra based on rotating frame spin relaxation allows separate examination of components from aggregates and disordered regions. Application to a comparison of two different monoclonal antibodies and to detection of partial pH denaturation of a monoclonal antibody illustrates the procedure. PMID:26653763

  9. Spin wave damping in periodic and quasiperiodic magnonic structures

    NASA Astrophysics Data System (ADS)

    Rychły, J.; Kłos, J. W.; Krawczyk, M.

    2016-05-01

    We investigated the lifetime of spin wave (SW) eigenmodes in periodic and quasiperiodic sequences of Py and Co wires. These materials differ significantly in damping coefficients, therefore, the spatial distribution of the mode’s amplitude within the structure is important for the lifetime of collective SW excitations. Modes of the lower frequencies prefer to concentrate in Py wires, because of the lower ferromagnetic resonance (FMR) frequency for this material. This inhomogeneous distribution of amplitude of modes (with lower amplitude in material of higher damping and with higher amplitude in material of lower damping) is preferable for extending the lifetime of the collective excitations beyond the volume average of lifetimes for solid materials. We established the relation between the profile of the mode and its lifetime for periodic and quasiperiodic structures. We also performed comparative studies in order to find the differences resulting from complexity of the structure and enhancement of localization in the quasiperiodic system on the lifetime of SWs.

  10. Parton interpretation of the nucleon spin-dependent structure functions

    SciTech Connect

    Mankiewicz, L. ); Ryzak, Z. )

    1991-02-01

    We discuss the interpretation of the nucleon's polarized structure function {ital g}{sub 2}({ital x}). If the target state is represented by its Fock decomposition on the light cone, the operator-product expansion allows us to demonstrate that moments of {ital g}{sub 2}({ital x}) are related to overlap integrals between wave functions of opposite longitudinal polarizations. In the light-cone formalism such wave functions are related by the kinematical operator {ital scrY}, or light-cone parity. As a consequence, it can be shown that moments of {ital g}{sub 2} give information about the same parton wave function, or probability amplitude to find a certain parton configuration in the target which defines {ital g}{sub 1}({ital x}) or {ital F}{sub 2}({ital x}). Specific formulas are given, and possible applications to the phenomenology of the nucleon structure in QCD are discussed.

  11. Efficient spin transfer phenomena in Fe/MgO/GaAs structure

    NASA Astrophysics Data System (ADS)

    Park, Y. J.; Hickey, M. C.; Van Veenhuizen, M. J.; Chang, J.; Heiman, D.; Perry, C. H.; Moodera, J. S.

    2011-03-01

    The efficiency of spin polarized charge transfer was investigated in an Fe/MgO tunnel barrier/GaAs based structure using spin dependent photocurrent measurements, whereby a spin imbalance in carrier population was generated in the GaAs by circularly polarized light. The dominance of tunneling transport processes over Schottky emission gave rise to a high spin transfer efficiency of 35% under the photovoltaic mode of device operation. A spin dependent tunneling conductance associated with spin polarized electron transport was identified by the observation of phase changes. This transport prevails over the unpolarized electron and hole conduction over the bias range which corresponds to flat band conditions.

  12. Spin accumulation assisted by the Aharonov-Bohm-Fano effect of quantum dot structures.

    PubMed

    Gong, Wei-Jiang; Han, Yu; Wei, Guo-Zhu; Du, An

    2012-01-01

    : We investigate the spin accumulations of Aharonov-Bohm interferometers with embedded quantum dots by considering spin bias in the leads. It is found that regardless of the interferometer configurations, the spin accumulations are closely determined by their quantum interference features. This is mainly manifested in the dependence of spin accumulations on the threaded magnetic flux and the nonresonant transmission process. Namely, the Aharonov-Bohm-Fano effect is a necessary condition to achieve the spin accumulation in the quantum dot of the resonant channel. Further analysis showed that in the double-dot interferometer, the spin accumulation can be detailedly manipulated. The spin accumulation properties of such structures offer a new scheme of spin manipulation. When the intradot Coulomb interactions are taken into account, we find that the electron interactions are advantageous to the spin accumulation in the resonant channel. PMID:22985404

  13. Spin accumulation assisted by the Aharonov-Bohm-Fano effect of quantum dot structures

    PubMed Central

    2012-01-01

    We investigate the spin accumulations of Aharonov-Bohm interferometers with embedded quantum dots by considering spin bias in the leads. It is found that regardless of the interferometer configurations, the spin accumulations are closely determined by their quantum interference features. This is mainly manifested in the dependence of spin accumulations on the threaded magnetic flux and the nonresonant transmission process. Namely, the Aharonov-Bohm-Fano effect is a necessary condition to achieve the spin accumulation in the quantum dot of the resonant channel. Further analysis showed that in the double-dot interferometer, the spin accumulation can be detailedly manipulated. The spin accumulation properties of such structures offer a new scheme of spin manipulation. When the intradot Coulomb interactions are taken into account, we find that the electron interactions are advantageous to the spin accumulation in the resonant channel. PMID:22985404

  14. Superalloy Disk With Dual-Grain Structure Spin Tested

    NASA Technical Reports Server (NTRS)

    Gayda, John; Kantzos, Pete T.

    2003-01-01

    Advanced nickel-base disk alloys for future gas turbine engines will require greater temperature capability than current alloys, but they must also continue to deliver safe, reliable operation. An advanced, nickel-base disk alloy, designated Alloy 10, was selected for evaluation in NASA s Ultra Safe Propulsion Project. Early studies on small test specimens showed that heat treatments that produced a fine grain microstructure promoted high strength and long fatigue life in the bore of a disk, whereas heat treatments that produced a coarse grain microstructure promoted optimal creep and crack growth resistance in the rim of a disk. On the basis of these results, the optimal combination of performance and safety might be achieved by utilizing a heat-treatment technology that could produce a fine grain bore and coarse grain rim in a nickel-base disk. Alloy 10 disks that were given a dual microstructure heat treatment (DMHT) were obtained from NASA s Ultra-Efficient Engine Technology (UEET) Program for preliminary evaluation. Data on small test specimens machined from a DMHT disk were encouraging. However, the benefit of the dual grain structure on the performance and reliability of the entire disk still needed to be demonstrated. For this reason, a high temperature spin test of a DMHT disk was run at 20 000 rpm and 1500 F at the Balancing Company of Dayton, Ohio, under the direction of NASA Glenn Research Center personnel. The results of that test showed that the DMHT disk exhibited significantly lower crack growth than a disk with a fine grain microstructure. In addition, the results of these tests could be accurately predicted using a two-dimensional, axisymmetric finite element analysis of the DMHT disk. Although the first spin test demonstrated a significant performance advantage associated with the DMHT technology, a second spin test on the DMHT disk was run to determine burst margin. The disk burst in the web at a very high speed, over 39 000 rpm, in line with

  15. Stability and internal structure of vortices in spin-1 Bose-Einstein condensates with conserved magnetization

    NASA Astrophysics Data System (ADS)

    Lovegrove, Justin; Borgh, Magnus O.; Ruostekoski, Janne

    2016-03-01

    We demonstrate how conservation of longitudinal magnetization can have pronounced effects on both stability and structure of vortices in the atomic spin-1 Bose-Einstein condensate by providing a systematic characterization of nonsingular and singular vortex states. Constructing spinor wave functions for vortex states that continuously connect ferromagnetic and polar phases, we systematically derive analytic models for nonrotating cores of different singular vortices and for composite defect states with distinct small- and large-distance topology. We explain how the conservation law provides a stabilizing mechanism when the coreless vortex imprinted on the condensate relaxes in the polar regime of interatomic interactions. The resulting structure forms a composite defect: The inner ferromagnetic coreless vortex deforms toward an outer singly quantized polar vortex. We also numerically show how other even more complex hierarchies of vortex-core topologies may be stabilized. Moreover, we analyze the structure of the coreless vortex also in a ferromagnetic condensate and show how reducing magnetization leads to a displacement of the vortex from the trap center and eventually to the deformation and splitting of its core where a singular vortex becomes a lower-energy state. For the case of singular vortices, we find that the stability and the core structure are notably less influenced by the conservation of magnetization.

  16. Longitudinal Field μSR Study of Spin Dynamics and Onset of Magnetic Correlations in LiHoxY1-xF4

    NASA Astrophysics Data System (ADS)

    Chen, K.; Johnson, R. C.; Giblin, S. R.; Lord, J. S.; Amato, A.; Baines, C.; Lascialfari, A.; Tkachuk, A. M.; Barbara, B.; Malkin, B. Z.; Graf, M. J.

    2010-03-01

    Nanomagnets - non-interacting spins typically imbedded in a solid host material - are intensely studied for applications ranging from high density data storage to quantum computing. We are studying the magnetic ion Ho^3+ spin dynamics in LiHoxY1-xF4 in the dilute limit (x << 1) using the muon spin relaxation in applied longitudinal magnetic fields as a function of temperature and magnetic field strength. At low concentrations (x <= 0.01) and for all magnetic field values studied, the spin lattice relaxation rate, 1/T1, shows a characteristic peak, usually associated with relaxation by spin fluctuations, near T = 10 K; this peak is consistent with the single-ion energy level diagram of Ho^3+. At larger x this peak is lost in low fields; stronger fields (> 600 G) restore the peak but show qualitatively different low temperature behavior. This suggests that both magnetic disorder and Ho-Ho interactions play an increasingly important role at larger x values.

  17. Changes in the unoccupied electronic structure of the spin crossover molecule [Co(dpzca)2

    NASA Astrophysics Data System (ADS)

    Liu, Yang; Zhang, Xin; Enders, Axel; Dowben, Peter; Luo, Jian; Zhang, Jian; N'diaye, Alpha

    We have investigated the changes in the unoccupied electronic structure of the spin crossover molecule - [Co(dpzca)2] using X-ray absorption spectroscopy (XAS) and have compared the results with magnetometry (SQUID) measurements. The studies of the variable temperature of the electronic structure of this cobalt complex with symmetric pyrazine imide ligands, -(2-pyrazylcarbonyl)-2-pyrazinecarboxamide, i.e. [Co(dpzca)2], are consistent with density functional theory (DFT). The temperature dependence of the occupancy of the high-spin state and low-spin state molecular orbital states, the unoccupied eg/t2g ratio from XAS and high spin state to low spin state ratio from molecular magnetic susceptibility χMT indicates that the low spin state is not a zero spin state, but simply a lower moment state that would occur below the spin crossover transition of [Co(dpzca)2].

  18. Nuclear magnetic relaxation induced by exchange-mediated orientational randomization: Longitudinal relaxation dispersion for a dipole-coupled spin-1/2 pair

    NASA Astrophysics Data System (ADS)

    Chang, Zhiwei; Halle, Bertil

    2013-10-01

    In complex biological or colloidal samples, magnetic relaxation dispersion (MRD) experiments using the field-cycling technique can characterize molecular motions on time scales ranging from nanoseconds to microseconds, provided that a rigorous theory of nuclear spin relaxation is available. In gels, cross-linked proteins, and biological tissues, where an immobilized macromolecular component coexists with a mobile solvent phase, nuclear spins residing in solvent (or cosolvent) species relax predominantly via exchange-mediated orientational randomization (EMOR) of anisotropic nuclear (electric quadrupole or magnetic dipole) couplings. The physical or chemical exchange processes that dominate the MRD typically occur on a time scale of microseconds or longer, where the conventional perturbation theory of spin relaxation breaks down. There is thus a need for a more general relaxation theory. Such a theory, based on the stochastic Liouville equation (SLE) for the EMOR mechanism, is available for a single quadrupolar spin I = 1. Here, we present the corresponding theory for a dipole-coupled spin-1/2 pair. To our knowledge, this is the first treatment of dipolar MRD outside the motional-narrowing regime. Based on an analytical solution of the spatial part of the SLE, we show how the integral longitudinal relaxation rate can be computed efficiently. Both like and unlike spins, with selective or non-selective excitation, are treated. For the experimentally important dilute regime, where only a small fraction of the spin pairs are immobilized, we obtain simple analytical expressions for the auto-relaxation and cross-relaxation rates which generalize the well-known Solomon equations. These generalized results will be useful in biophysical studies, e.g., of intermittent protein dynamics. In addition, they represent a first step towards a rigorous theory of water 1H relaxation in biological tissues, which is a prerequisite for unravelling the molecular basis of soft

  19. Spin-mapping of coal structures with ESE and ENDOR

    SciTech Connect

    Belford, R.L.; Clarkson, R.B.

    1991-12-01

    The goals of this program include developing a system for the analysis of the chemical forms of organic sulfur in coal and for study of coal particle surfaces by multifrequency EPR spectroscopy, ENDOR, and ESE spectroscopy and Applying it to coals, to the effects of treatment upon their sulfur-containing organic components, and to related carbonaceous materials (chars and the like). The approach is to utilize the naturally-occurring unpaired electrons in the organic structures of coals as spies to provide molecular structure information, reading out the information with Electron Paramagnetic Resonance (EPR) spectroscopy. Several forms of EPR are employed: Multifrequency continuous-wave (CW) EPR, from 1 GHz to 240 GHz source frequency; electron-nuclear double resonance (ENDOR), in which NMR spectra at paramagnetic centers are obtained by EPR detection; and pulsed EPR, including ESE (Electron Spin Echo) spectroscopy.

  20. High-spin yrast structure of {sup 159}Ho

    SciTech Connect

    Ollier, J.; Simpson, J.; Riley, M. A.; Wang, X.; Aguilar, A.; Teal, C.; Paul, E. S.; Nolan, P. J.; Petri, M.; Rigby, S. V.; Thomson, J.; Unsworth, C.; Carpenter, M. P.; Janssens, R. V. F.; Lauritsen, T.; Zhu, S.; Darby, I. G.; Hartley, D. J.; Kondev, F. G.

    2011-08-15

    An investigation of the yrast structure of the odd-Z {sup 159}Ho nucleus to high spin has been performed. The {sup 159}Ho nucleus was populated by the reaction {sup 116}Cd({sup 48}Ca,p4n{gamma}) at a beam energy of 215 MeV, and resulting {gamma} decays were detected by the Gammasphere spectrometer. The h{sub 11/2} yrast band has been significantly extended up to I{sup {pi}=}75/2{sup -} (tentatively 79/2{sup -}). A lower frequency limit for the second (h{sub 11/2}){sup 2} proton alignment was extracted consistent with the systematics of this alignment frequency, indicating an increased deformation with neutron number in the Ho isotopes. The energy-level splitting between the signature partners in the h{sub 11/2} structures of the Ho isotopes and the neighboring N=92 isotones is discussed.

  1. Study of electronic structure and spin polarization of dysprosium

    SciTech Connect

    Mund, H. S.

    2015-06-24

    In this paper, I have presented the spin-dependent momentum density of ferromagnetic dysprosium using spin polarized relativistic Korringa-Kohn-Rostoker method. A fully relativistic approach has been used to determine the magnetic Compton profile. The density of state in term of majority-spin and minority-spin of Dy also calculated using SPR-KKR. The magnetic Compton profile discussed in term of 4f and diffused electrons.

  2. Dynamical spin structure factor of one-dimensional interacting fermions

    NASA Astrophysics Data System (ADS)

    Zyuzin, Vladimir A.; Maslov, Dmitrii L.

    2015-02-01

    We revisit the dynamic spin susceptibility χ (q ,ω ) of one-dimensional interacting fermions. To second order in the interaction, backscattering results in a logarithmic correction to χ (q ,ω ) at q ≪kF , even if the single-particle spectrum is linearized near the Fermi points. Consequently, the dynamic spin structure factor Im χ (q ,ω ) is nonzero at frequencies above the single-particle continuum. In the boson language, this effect results from the marginally irrelevant backscattering operator of the sine-Gordon model. Away from the threshold, the high-frequency tail of Im χ (q ,ω ) due to backscattering is larger than that due to finite mass by a factor of kF/q . We derive the renormalization group equations for the coupling constants of the g -ology model at finite ω and q and find the corresponding expression for χ (q ,ω ) , valid to all orders in the interaction but not in the immediate vicinity of the continuum boundary, where the finite-mass effects become dominant.

  3. Spin orientation, structure, morphology, and magnetic properties of hematite nanoparticles

    NASA Astrophysics Data System (ADS)

    Xu, S.; Habib, A. H.; Gee, S. H.; Hong, Y. K.; McHenry, M. E.

    2015-05-01

    Monodisperse hematite (α-Fe2O3) nanoparticles were synthesized by forced hydrolysis of acidic Fe3+ solution. Rietveld analysis was applied to the X-ray powder diffraction data to refine the lattice constants and atomic positions. The lattice constants for a hexagonal unit cell were determined to be a ˜ 0.50327 and c ˜ 1.37521 nm. High resolution transmission electron microscopy was employed to study the morphology of the particles. Atomic scale micrographs and diffraction patterns from several zone axes were obtained. These reveal the high degree of crystallinity of the particles. A series of observations made on the particles by tilting them through a range of ±45° revealed the particles to be micaceous with stacking of platelets with well defined crystallographic orientations. The Morin transition in these nanoparticles was found to occur at 210 K, which is lower temperature than 263 K of bulk hematite. It was ascertained from the previous Mössbauer studies that the spin orientation for nano-sized hematite particle flips from 90° to 28° with respect to the c-axis of the hexagonal structure during the Morin transition, which is in contrast to that observed in bulk hematite where spin orientation flips from 90° to 0°.

  4. Spin orientation, structure, morphology, and magnetic properties of hematite nanoparticles

    SciTech Connect

    Xu, S.; Habib, A. H.; Gee, S. H.; Hong, Y. K.; McHenry, M. E.

    2015-05-07

    Monodisperse hematite (α-Fe{sub 2}O{sub 3}) nanoparticles were synthesized by forced hydrolysis of acidic Fe{sup 3+} solution. Rietveld analysis was applied to the X-ray powder diffraction data to refine the lattice constants and atomic positions. The lattice constants for a hexagonal unit cell were determined to be a ∼ 0.50327 and c ∼ 1.37521 nm. High resolution transmission electron microscopy was employed to study the morphology of the particles. Atomic scale micrographs and diffraction patterns from several zone axes were obtained. These reveal the high degree of crystallinity of the particles. A series of observations made on the particles by tilting them through a range of ±45° revealed the particles to be micaceous with stacking of platelets with well defined crystallographic orientations. The Morin transition in these nanoparticles was found to occur at 210 K, which is lower temperature than 263 K of bulk hematite. It was ascertained from the previous Mössbauer studies that the spin orientation for nano-sized hematite particle flips from 90° to 28° with respect to the c-axis of the hexagonal structure during the Morin transition, which is in contrast to that observed in bulk hematite where spin orientation flips from 90° to 0°.

  5. Electronic Structure, NMR, Spin-Spin Coupling, and Noncovalent Interactions in Aromatic Amino Acid Based Ionic Liquids.

    PubMed

    Rao, Soniya S; Gejji, Shridhar P

    2016-07-21

    Noncovalent interactions accompanying phenylalanine (Phe), tryptophan (Trp), and tyrosine (Tyr) amino acids based ionic liquids (AAILs) composed of 1-methyl-3-butyl-imidazole and its methyl-substituted derivative as cations have been analyzed employing the dispersion corrected density functional theory. It has been shown that cation-anion binding in these bioionic ILs is primarily facilitated through hydrogen bonding in addition to lp---π and CH---π interactions those arising from aromatic moieties which can be probed through (1)H and (13)C NMR spectra calculated from the gauge independent atomic orbital method. Characteristic NMR spin-spin coupling constants across hydrogen bonds of ion pair structures viz., Fermi contact, spin-orbit and spin-dipole terms show strong dependence on mutual orientation of cation with the amino acid anion. The spin-spin coupling mechanism transmits spin polarization via electric field effect originating from lp---π interactions whereas the electron delocalization from lone pair on the carbonyl oxygen to antibonding C-H orbital is facilitated by hydrogen bonding. It has been demonstrated that indirect spin-spin coupling constants across the hydrogen bonds correlate linearly with hydrogen bond distances. The binding energies and dissected nucleus independent chemical shifts (NICS) document mutual reduction of aromaticity of hydrogen bonded ion pairs consequent to localization of π-character. Moreover the nature and type of such noncovalent interactions governing the in-plane and out-of-plane NICS components provide a measure of diatropic and paratropic currents for the aromatic rings of varying size in AAILs. Besides the direction of frequency shifts of characteristic C═O and NH stretching vibrations in the calculated vibrational spectra has been rationalized. PMID:27336283

  6. Longitudinal Double-Spin Asymmetry and Cross Section for Inclusive Jet Production in Polarized Proton Collisions at {radical}(s)=200 GeV

    SciTech Connect

    Abelev, B. I.; Bielcik, J.; Bielcikova, J.; Caines, H.; Catu, O.; Chikanian, A.; Du, F.; Finch, E.; Harris, J. W.; Heinz, M.; Lamont, M. A. C.; Lin, G.; Majka, R.; Nattrass, C.; Salur, S.; Sandweiss, J.; Smirnov, N.; Witt, R.; Aggarwal, M. M.; Bhati, A. K.

    2006-12-22

    We report a measurement of the longitudinal double-spin asymmetry A{sub LL} and the differential cross section for inclusive midrapidity jet production in polarized proton collisions at {radical}(s)=200 GeV. The cross section data cover transverse momenta 5

  7. Longitudinal Double-Spin Asymmetry and Cross Section for Inclusive Jet Production in Polarized Proton Collisions at s=200GeV

    NASA Astrophysics Data System (ADS)

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Amonett, J.; Anderson, B. D.; Anderson, M.; Arkhipkin, D.; Averichev, G. S.; Bai, Y.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Bekele, S.; Belaga, V. V.; Bellingeri-Laurikainen, A.; Bellwied, R.; Benedosso, F.; Bhardwaj, S.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Blyth, S.-L.; Bonner, B. E.; Botje, M.; Bouchet, J.; Brandin, A. V.; Bravar, A.; Burton, T. P.; Bystersky, M.; Cadman, R. V.; Cai, X. Z.; Caines, H.; Sánchez, M. Calderón De La Barca; Castillo, J.; Catu, O.; Cebra, D.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Coffin, J. P.; Cormier, T. M.; Cosentino, M. R.; Cramer, J. G.; Crawford, H. J.; Das, D.; Das, S.; Dash, S.; Daugherity, M.; de Moura, M. M.; Dedovich, T. G.; Dephillips, M.; Derevschikov, A. A.; Didenko, L.; Dietel, T.; Djawotho, P.; Dogra, S. M.; Dong, W. J.; Dong, X.; Draper, J. E.; Du, F.; Dunin, V. B.; Dunlop, J. C.; Mazumdar, M. R. Dutta; Eckardt, V.; Edwards, W. R.; Efimov, L. G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Fu, J.; Gagliardi, C. A.; Gaillard, L.; Ganti, M. S.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J. E.; Gorbunov, Y. G.; Gos, H.; Grebenyuk, O.; Grosnick, D.; Guertin, S. M.; Guimaraes, K. S. F. F.; Gupta, N.; Gutierrez, T. D.; Haag, B.; Hallman, T. J.; Hamed, A.; Harris, J. W.; He, W.; Heinz, M.; Henry, T. W.; Hepplemann, S.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffman, A. M.; Hoffmann, G. W.; Horner, M. J.; Huang, H. Z.; Huang, S. L.; Hughes, E. W.; Humanic, T. J.; Igo, G.; Jacobs, P.; Jacobs, W. W.; Jakl, P.; Jia, F.; Jiang, H.; Jones, P. G.; Judd, E. G.; Kabana, S.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Khodyrev, V. Yu.; Kim, B. C.; Kiryluk, J.; Kisiel, A.; Kislov, E. M.; Klein, S. R.; Kocoloski, A.; Koetke, D. D.; Kollegger, T.; Kopytine, M.; Kotchenda, L.; Kouchpil, V.; Kowalik, K. L.; Kramer, M.; Kravtsov, P.; Kravtsov, V. I.; Krueger, K.; Kuhn, C.; Kulikov, A. I.; Kumar, A.; Kuznetsov, A. A.; Lamont, M. A. C.; Landgraf, J. M.; Lange, S.; Lapointe, S.; Laue, F.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, C.-H.; Lehocka, S.; Levine, M. J.; Li, C.; Li, Q.; Li, Y.; Lin, G.; Lin, X.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, J.; Liu, L.; Liu, Z.; Ljubicic, T.; Llope, W. J.; Long, H.; Longacre, R. S.; Love, W. A.; Lu, Y.; Ludlam, T.; Lynn, D.; Ma, G. L.; Ma, J. G.; Ma, Y. G.; Magestro, D.; Mahapatra, D. P.; Majka, R.; Mangotra, L. K.; Manweiler, R.; Margetis, S.; Markert, C.; Martin, L.; Matis, H. S.; Matulenko, Yu. A.; McClain, C. J.; McShane, T. S.; Melnick, Yu.; Meschanin, A.; Millane, J.; Miller, M. L.; Minaev, N. G.; Mioduszewski, S.; Mironov, C.; Mischke, A.; Mishra, D. K.; Mitchell, J.; Mohanty, B.; Molnar, L.; Moore, C. F.; Morozov, D. A.; Munhoz, M. G.; Nandi, B. K.; Nattrass, C.; Nayak, T. K.; Nelson, J. M.; Netrakanti, P. K.; Nogach, L. V.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okorokov, V.; Oldenburg, M.; Olson, D.; Pachr, M.; Pal, S. K.; Panebratsev, Y.; Panitkin, S. Y.; Pavlinov, A. I.; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Phatak, S. C.; Picha, R.; Planinic, M.; Pluta, J.; Poljak, N.; Porile, N.; Porter, J.; Poskanzer, A. M.; Potekhin, M.; Potrebenikova, E.; Potukuchi, B. V. K. S.; Prindle, D.; Pruneau, C.; Putschke, J.; Rakness, G.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Razin, S. V.; Reinnarth, J.; Relyea, D.; Ridiger, A.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Rose, A.; Roy, C.; Ruan, L.; Russcher, M. J.; Sahoo, R.; Sakuma, T.; Salur, S.; Sandweiss, J.; Sarsour, M.; Sazhin, P. S.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shabetai, A.; Shahaliev, E.; Shao, M.; Sharma, M.; Shen, W. Q.; Shimanskiy, S. S.; Sichtermann, E. P.; Simon, F.; Singaraju, R. N.; Smirnov, N.; Snellings, R.; Sood, G.; Sorensen, P.; Sowinski, J.; Speltz, J.; Spinka, H. M.; Srivastava, B.; Stadnik, A.; Stanislaus, T. D. S.; Stock, R.; Stolpovsky, A.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Sugarbaker, E.; Sumbera, M.; Sun, Z.; Surrow, B.; Swanger, M.; Symons, T. J. M.; de Toledo, A. Szanto; Tai, A.; Takahashi, J.; Tang, A. H.; Tarnowsky, T.; Thein, D.; Thomas, J. H.; Timmins, A. R.; Timoshenko, S.; Tokarev, M.; Trainor, T. A.; Trentalange, S.; Tribble, R. E.; Tsai, O. D.; Ulery, J.; Ullrich, T.; Underwood, D. G.; Buren, G. Van; van der Kolk, N.; van Leeuwen, M.; Molen, A. M. Vander; Varma, R.; Vasilevski, I. M.; Vasiliev, A. N.; Vernet, R.; Vigdor, S. E.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Waggoner, W. T.; Wang, F.; Wang, G.; Wang, J. S.; Wang, X. L.; Wang, Y.; Watson, J. W.; Webb, J. C.; Westfall, G. D.; Wetzler, A.; Whitten, C., Jr.; Wieman, H.; Wissink, S. W.; Witt, R.; Wood, J.; Wu, J.; Xu, N.; Xu, Q. H.; Xu, Z.; Yepes, P.; Yoo, I.-K.; Yurevich, V. I.; Zhan, W.; Zhang, H.; Zhang, W. M.; Zhang, Y.; Zhang, Z. P.; Zhao, Y.; Zhong, C.; Zoulkarneev, R.; Zoulkarneeva, Y.; Zubarev, A. N.; Zuo, J. X.

    2006-12-01

    We report a measurement of the longitudinal double-spin asymmetry ALL and the differential cross section for inclusive midrapidity jet production in polarized proton collisions at s=200GeV. The cross section data cover transverse momenta 5

  8. Precision measurement of the longitudinal double-spin asymmetry for inclusive jet production in polarized proton collisions at √s = 200 GeV

    DOE PAGESBeta

    Adamczyk, L.

    2015-08-26

    We report a new measurement of the midrapidity inclusive jet longitudinal double-spin asymmetry, ALL, in polarized pp collisions at center-of-mass energy √s = 200 GeV. The STAR data place stringent constraints on polarized parton distribution functions extracted at next-to-leading order from global analyses of inclusive deep-inelastic scattering (DIS), semi-inclusive DIS, and RHIC pp data. Lastly, the measured asymmetries provide evidence at the 3σ level for positive gluon polarization in the Bjorken-x region x > 0.05 .

  9. Precision measurement of the longitudinal double-spin asymmetry for inclusive jet production in polarized proton collisions at √s = 200 GeV

    SciTech Connect

    Adamczyk, L.

    2015-08-26

    We report a new measurement of the midrapidity inclusive jet longitudinal double-spin asymmetry, ALL, in polarized pp collisions at center-of-mass energy √s = 200 GeV. The STAR data place stringent constraints on polarized parton distribution functions extracted at next-to-leading order from global analyses of inclusive deep-inelastic scattering (DIS), semi-inclusive DIS, and RHIC pp data. Lastly, the measured asymmetries provide evidence at the 3σ level for positive gluon polarization in the Bjorken-x region x > 0.05 .

  10. Precision Measurement of the Longitudinal Double-Spin Asymmetry for Inclusive Jet Production in Polarized Proton Collisions at √{s }=200 GeV

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Contin, G.; Cramer, J. G.; Crawford, H. J.; Cudd, A. B.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kosarzewski, L. K.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Olvitt, D. L.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szelezniak, M. A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zawisza, Y.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2015-08-01

    We report a new measurement of the midrapidity inclusive jet longitudinal double-spin asymmetry, AL L, in polarized p p collisions at center-of-mass energy √{s }=200 GeV . The STAR data place stringent constraints on polarized parton distribution functions extracted at next-to-leading order from global analyses of inclusive deep-inelastic scattering (DIS), semi-inclusive DIS, and RHIC p p data. The measured asymmetries provide evidence at the 3 σ level for positive gluon polarization in the Bjorken-x region x >0.05 .

  11. Precision Measurement of the Longitudinal Double-Spin Asymmetry for Inclusive Jet Production in Polarized Proton Collisions at sqrt[s]=200  GeV.

    PubMed

    Adamczyk, L; Adkins, J K; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Alford, J; Anson, C D; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Banerjee, A; Beavis, D R; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Borowski, W; Bouchet, J; Brandin, A V; Brovko, S G; Bültmann, S; Bunzarov, I; Burton, T P; Butterworth, J; Caines, H; Calderón de la Barca Sánchez, M; Campbell, J M; Cebra, D; Cendejas, R; Cervantes, M C; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, L; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chwastowski, J; Codrington, M J M; Contin, G; Cramer, J G; Crawford, H J; Cudd, A B; Cui, X; Das, S; Davila Leyva, A; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; Derradi de Souza, R; Dhamija, S; di Ruzza, B; Didenko, L; Dilks, C; Ding, F; Djawotho, P; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Engle, K S; Eppley, G; Eun, L; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Fedorisin, J; Filip, P; Finch, E; Fisyak, Y; Flores, C E; Gagliardi, C A; Gangadharan, D R; Garand, D; Geurts, F; Gibson, A; Girard, M; Gliske, S; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, A; Gupta, S; Guryn, W; Haag, B; Hamed, A; Han, L-X; Haque, R; Harris, J W; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, B; Huang, H Z; Huang, X; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Kesich, A; Khan, Z H; Kikola, D P; Kisel, I; Kisiel, A; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Kosarzewski, L K; Kotchenda, L; Kraishan, A F; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; LeVine, M J; Li, C; Li, W; Li, X; Li, X; Li, Y; Li, Z M; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, G L; Ma, Y G; Madagodagettige Don, D M M D; Mahapatra, D P; Majka, R; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; McShane, T S; Minaev, N G; Mioduszewski, S; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nelson, J M; Nigmatkulov, G; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Ohlson, A; Okorokov, V; Oldag, E W; Olvitt, D L; Pachr, M; Page, B S; Pal, S K; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlak, T; Pawlik, B; Pei, H; Perkins, C; Peryt, W; Pile, P; Planinic, M; Pluta, J; Poljak, N; Poniatowska, K; Porter, J; Poskanzer, A M; Pruthi, N K; Przybycien, M; Pujahari, P R; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, R; Raniwala, S; Ray, R L; Riley, C K; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ross, J F; Roy, A; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandweiss, J; Sangaline, E; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Singaraju, R N; Skoby, M J; Smirnov, D; Smirnov, N; Solanki, D; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Sun, X; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; Szelezniak, M A; Takahashi, J; Tang, A H; Tang, Z; Tarnowsky, T; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Trzeciak, B A; Tsai, O D; Turnau, J; Ullrich, T; Underwood, D G; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Vertesi, R; Videbæk, F; Viyogi, Y P; Vokal, S; Vossen, A; Wada, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, X L; Wang, Y; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xiao, Z; Xie, W; Xin, K; Xu, H; Xu, J; Xu, N; Xu, Q H; Xu, Y; Xu, Z; Yan, W; Yang, C; Yang, Y; Yang, Y; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Yu, N; Zawisza, Y; Zbroszczyk, H; Zha, W; Zhang, J B; Zhang, J L; Zhang, S; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, F; Zhao, J; Zhong, C; Zhu, X; Zhu, Y H; Zoulkarneeva, Y; Zyzak, M

    2015-08-28

    We report a new measurement of the midrapidity inclusive jet longitudinal double-spin asymmetry, A_{LL}, in polarized pp collisions at center-of-mass energy sqrt[s]=200  GeV. The STAR data place stringent constraints on polarized parton distribution functions extracted at next-to-leading order from global analyses of inclusive deep-inelastic scattering (DIS), semi-inclusive DIS, and RHIC pp data. The measured asymmetries provide evidence at the 3σ level for positive gluon polarization in the Bjorken-x region x>0.05. PMID:26371644

  12. Structural Relationships between Social Activities and Longitudinal Trajectories of Depression among Older Adults

    ERIC Educational Resources Information Center

    Hong, Song-Iee; Hasche, Leslie; Bowland, Sharon

    2009-01-01

    Purpose: This study examines the structural relationships between social activities and trajectories of late-life depression. Design and Methods: Latent class analysis was used with a nationally representative sample of older adults (N = 5,294) from the Longitudinal Study on Aging II to classify patterns of social activities. A latent growth curve…

  13. Structured Weyl Points in Spin-Orbit Coupled Fermionic Superfluids

    NASA Astrophysics Data System (ADS)

    Xu, Yong; Zhang, Fan; Zhang, Chuanwei

    2015-12-01

    We demonstrate that a Weyl point, widely examined in 3D Weyl semimetals and superfluids, can develop a pair of nondegenerate gapless spheres. Such a bouquet of two spheres is characterized by three distinct topological invariants of manifolds with full energy gaps, i.e., the Chern number of a 0D point inside one developed sphere, the winding number of a 1D loop around the original Weyl point, and the Chern number of a 2D surface enclosing the whole bouquet. We show that such structured Weyl points can be realized in the superfluid quasiparticle spectrum of a 3D degenerate Fermi gas subject to spin-orbit couplings and Zeeman fields, which supports Fulde-Ferrell superfluids as the ground state.

  14. Suppression of Walker breakdown in magnetic domain wall propagation through structural control of spin wave emission

    NASA Astrophysics Data System (ADS)

    Burn, David M.; Atkinson, Del

    2013-06-01

    The control of individual magnetic domain walls has potential for future spintronic memory and data processing applications. The speed and reliability of such devices are determined by the dynamic properties of the domain walls. Typically, spin precession limitations lead to Walker breakdown, limiting wall velocity resulting in low mobility. Here, we show the suppression of Walker breakdown by the careful design of small amplitude periodic nanowire structuring to match the periodicity of domain wall spin structure transformations. This opens up a channel for energy dissipation via spin wave emission, allowing a domain wall to maintain its spin structure during propagation.

  15. Localization and spin transport in honeycomb structures with spin-orbit coupling

    NASA Astrophysics Data System (ADS)

    de Queiroz, S. L. A.

    2015-11-01

    Transfer-matrix methods are used for a tight-binding description of electron transport in graphenelike geometries in the presence of spin-orbit couplings. Application of finite-size scaling and phenomenological renormalization techniques shows that, for strong enough spin-orbit interactions and increasing on-site disorder, this system undergoes a metal-insulator transition characterized by the exponents ν =2.71 (8 ) , η =0.174 (2 ) . We show how one can extract information regarding spin polarization decay with distance from an injection edge, from the evolution of wave-function amplitudes in the transfer-matrix approach. For (relatively weak) spin-orbit coupling intensity μ , we obtain that the characteristic length Λs for spin-polarization decay behaves as Λs∝μ-2 .

  16. Selecting a Separable Parametric Spatiotemporal Covariance Structure for Longitudinal Imaging Data

    PubMed Central

    George, Brandon; Aban, Inmaculada

    2014-01-01

    Longitudinal imaging studies allow great insight into how the structure and function of a subject’s internal anatomy changes over time. Unfortunately, the analysis of longitudinal imaging data is complicated by inherent spatial and temporal correlation: the temporal from the repeated measures, and the spatial from the outcomes of interest being observed at multiple points in a patients body. We propose the use of a linear model with a separable parametric spatiotemporal error structure for the analysis of repeated imaging data. The model makes use of spatial (exponential, spherical, and Matérn) and temporal (compound symmetric, autoregressive-1, Toeplitz, and unstructured) parametric correlation functions. A simulation study, inspired by a longitudinal cardiac imaging study on mitral regurgitation patients, compared different information criteria for selecting a particular separable parametric spatiotemporal correlation structure as well as the effects on Type I and II error rates for inference on fixed effects when the specified model is incorrect. Information criteria were found to be highly accurate at choosing between separable parametric spatiotemporal correlation structures. Misspecification of the covariance structure was found to have the ability to inflate the Type I error or have an overly conservative test size, which corresponded to decreased power. An example with clinical data is given illustrating how the covariance structure procedure can be done in practice, as well as how covariance structure choice can change inferences about fixed effects. PMID:25293361

  17. Magnetic structure map for face-centered tetragonal iron: Appearance of a collinear spin structure

    NASA Astrophysics Data System (ADS)

    Reith, D.; Podloucky, R.; Marsman, M.; Bedolla-Velazquez, P. O.; Mohn, P.

    2014-07-01

    For fcc and tetragonal distorted fct iron a large number of magnetic configurations as a function of crystal structural parameters were studied by means of density functional theory concepts. The stability of magnetic structures was defined by the magnetic reorientation energy ΔEreori as the difference of the total energy of configuration i and that of the fcc ferromagnetic state. The cluster expansion technique was applied to six volumes deriving ΔEreor for more than 90 000 collinear spin structures at each volume. Structures with low ΔEreor were tetragonally distorted according to a two-dimensional mesh defined by volume per atom V and c /a ratio. At each mesh point ΔEreor for all collinear structures were compared to results for spin spirals (SSs) which were calculated on a grid of propagation directions, and then the lowest ΔEreor defined the magnetic structure map. Three local minima were identified and for each of the minima SSs were calculated on a fine grid of propagation vectors. At the minimum with V =10.6 Å3 and 0.94≤c/a≤1.01 a hitherto unknown simple collinear spin structure with four atoms per fct unit cell was the most stable one. It consists of two atoms with antiferromagnetically ordered local moments of ±1.8μB and of two atoms with zero local moment.

  18. Spin-mapping of coal structures with ESE and ENDOR

    SciTech Connect

    Belford, R.L.; Clarkson, R.B.

    1990-09-01

    A nondestructive method to determine the atomic and molecular structures present in the organic (maceral) components of whole coal and coal products has been sought for many years. This program of research is designed to address that analytical need by applying advanced electron magnetic resonance techniques to the determination of coal molecular structure. Structural information has be obtained by using the naturally occurring unpaired electrons in coal as observation posts'' from which to survey neighboring atoms through the electron-nuclear hyperfine interaction. Such an overall approach has been termed ELECTRON SPIN MAPPING of coal structure. New techniques like 2-dimensional ENDOR and ESE spectroscopies and multifrequency EPR, including the world's first S-band ESE spectrometer and one of the first W-band instruments, which we have developed in our laboratory, were employed in the determination. The materials studied were well separated macerals obtained by density gradient centrifugation techniques from Illinois {number sign}6 coals, a well as whole Illinois {number sign}6, {number sign}5, and Argonne Premium Sample Coals. model compounds, chosen to represent molecular structures typical of those believed to exist in coal also were studied by the various electron magnetic resonance (EMR) methods. Utilizing the various EMR methods available in our laboratory, we studied approaches to determine parameters that direcly reflect the atomic and molecular structure of coal. The naturally occurring unpaired electrons in coal were utilized as probes of their local environment, which they reflect through hyperfine interactions with neighboring 1 > 0 nuclei (eg, {sup 1}H, {sup 13}C).

  19. Spin current injection by spin Seebeck and spin pumping effects in yttrium iron garnet/Pt structures

    NASA Astrophysics Data System (ADS)

    da Silva, G. L.; Vilela-Leão, L. H.; Rezende, S. M.; Azevedo, A.

    2012-04-01

    It is reported an investigation of pure spin current injection in Pt strips deposited on yttrium iron garnet (YIG) films by means of the spin pumping (SPE) and spin Seebeck (SSE) effects. Both effects were characterized by measuring the DC voltage created along the Pt strips by means of the inverse spin Hall effect (VISHE). SPE and SSE are simultaneously activated by exciting the ferromagnetic resonance (FMR) of the YIG film at the same time that a temperature gradient is created along the sample length. While the FMR signal is little affected by the temperature gradient, the voltage measured at the Pt strip placed at the lower temperature end exhibits a very challenging behavior. The voltage excited by the FMR uniform mode increases by six times as the temperature difference (ΔT) between the two ends of the YIG slab changes from 0 to 12 K. In contrast the VISHE generated by other magnetostatic spin-wave modes decreases to zero as ΔT varies from 0 to 12 K.

  20. Study of spatial spin-modulated structures by Mössbauer spectroscopy using SpectrRelax

    SciTech Connect

    Matsnev, Mikhail E. Rusakov, Vyacheslav S.

    2014-10-27

    SpectrRelax is an application for analysis and fitting of absorption and emission Mössbauer spectra. It includes a large selection of static and relaxation spectrum models, and allows fitting and searching for optimal model parameters. Recently, we have added new models for Mössbauer spectra of nuclides in spatial spin modulated structures. In these structures, spin density or direction changes in a periodic way along a single direction, and this wave is incommensurate with the underlying lattice. The models include Spin/Charge density wave, where the shape of this wave is represented as a sum of odd harmonics, Anharmonic spin modulation where the spin direction has a cycloidal type modulation, and a Spiral-like spin structure, in which magnetic moments rotate in a plane perpendicular to the wave propagation vector, forming a spiral.

  1. Precision Measurement of the Neutron Spin Asymmetries and Spin-dependent Structure Functions in the Valence Quark Region

    SciTech Connect

    Xiaochao Zheng; Konrad Aniol; David Armstrong; Todd Averett; William Bertozzi; Sebastien Binet; Etienne Burtin; Emmanuel Busato; Cornel Butuceanu; John Calarco; Alexandre Camsonne; Gordon Cates; Zhengwei Chai; Jian-ping Chen; Seonho Choi; Eugene Chudakov; Francesco Cusanno; Raffaele De Leo; Alexandre Deur; Sonja Dieterich; Dipangkar Dutta; John Finn; Salvatore Frullani; Haiyan Gao; Juncai Gao; Franco Garibaldi; Shalev Gilad; Ronald Gilman; Javier Gomez; Jens-ole Hansen; Douglas Higinbotham; Wendy Hinton; Tanja Horn; Cornelis De Jager; Xiaodong Jiang; Lisa Kaufman; James Kelly; Wolfgang Korsch; Kevin Kramer; John Lerose; David Lhuillier; Nilanga Liyanage; Demetrius Margaziotis; Frederic Marie; Pete Markowitz; Kathy Mccormick; Zein-eddine Meziani; Robert Michaels; Bryan Moffit; Sirish Nanda; Damien Neyret; Sarah Phillips; Anthony Powell; Thierry Pussieux; Bodo Reitz; Julie Roche; Michael Roedelbronn; Guy Ron; Marat Rvachev; Arunava Saha; Nikolai Savvinov; Jaideep Singh; Simon Sirca; Karl Slifer; Patricia Solvignon; Paul Souder; Daniel Steiner; Steffen Strauch; Vincent Sulkosky; William Tobias; Guido Urciuoli; Antonin Vacheret; Bogdan Wojtsekhowski; Hong Xiang; Yuan Xiao; Feng Xiong; Bin Zhang; Lingyan Zhu; Xiaofeng Zhu; Piotr Zolnierczuk

    2004-05-01

    We report on measurements of the neutron spin asymmetries A{sub 1,2}{sup n} and polarized structure functions g{sub 1,2}{sup n} at three kinematics in the deep inelastic region, with x = 0.33, 0.47 and .60 and Q{sub 2} = 2.7, 3.5 and 4.8 (GeV/c){sup 2}, respectively. These measurements were performed using a 5.7 GeV longitudinally-polarized electron beam and a polarized {sup 3}He target. The results for A{sub 1}{sup n} and g{sub 1}{sup n} at x = 0.33 are consistent with previous world data and, at the two higher x points, have improved the precision of the world data by about an order of magnitude. The new A{sub 1}{sup n} data show a zero crossing around x = 0.47 and the value at x = 0.60 is significantly positive. These results agree with a next-to-leading order QCD analysis of previous world data. The trend of data at high x agrees with constituent quark model predictions but disagrees with that from leading-order perturbative QCD (pQCD) assuming hadron helicity conservation. Results for A{sub 2}{sup n} and g{sub 2}{sup n} have a precision comparable to the best world data in this kinematic region. Combined with previous world data, the moment d{sub 2}{sup n} was evaluated and the new result has improved the precision of this quantity by about a factor of two. When combined with the world proton data, polarized quark distribution functions were extracted from the new g{sub 1}{sup n}/F{sub 1}{sup n} values based on the quark parton model. While results for {Delta}u/u agree well with predictions from various models, results for {Delta}d/d disagree with the leading-order pQCD prediction when hadron helicity conservation is imposed.

  2. Precision measurement of the neutron spin asymmetries and spin-dependent structure functions in the valence quark region

    SciTech Connect

    Zheng, X.; Bertozzi, W.; Chai, Z.; Dutta, D.; Gao, H.; Gilad, S.; Higinbotham, D.W.; Rvachev, M.; Sirca, S.; Xiang, H.; Xiao, Y.; Xiong, F.; Zhang, B.; Zhu, L.; Aniol, K.; Margaziotis, D.J.; Armstrong, D.S.; Butuceanu, C.; Finn, J.M.; Kramer, K.

    2004-12-01

    We report on measurements of the neutron spin asymmetries A{sub 1,2}{sup n} and polarized structure functions g{sub 1,2}{sup n} at three kinematics in the deep inelastic region, with x=0.33, 0.47, and 0.60 and Q{sup 2}=2.7, 3.5, and 4.8 (GeV/c){sup 2}, respectively. These measurements were performed using a 5.7 GeV longitudinally polarized electron beam and a polarized {sup 3}He target. The results for A{sub 1}{sup n} and g{sub 1}{sup n} at x=0.33 are consistent with previous world data and, at the two higher-x points, have improved the precision of the world data by about an order of magnitude. The new A{sub 1}{sup n} data show a zero crossing around x=0.47 and the value at x=0.60 is significantly positive. These results agree with a next-to-leading-order QCD analysis of previous world data. The trend of data at high x agrees with constituent quark model predictions but disagrees with that from leading-order perturbative QCD (PQCD) assuming hadron helicity conservation. Results for A{sub 2}{sup n} and g{sub 2}{sup n} have a precision comparable to the best world data in this kinematic region. Combined with previous world data, the moment d{sub 2}{sup n} was evaluated and the new result has improved the precision of this quantity by about a factor of 2. When combined with the world proton data, polarized quark distribution functions were extracted from the new g{sub 1}{sup n}/F{sub 1}{sup n} values based on the quark-parton model. While results for {delta}u/u agree well with predictions from various models, results for {delta}d/d disagree with the leading-order PQCD prediction when hadron helicity conservation is imposed.

  3. Calculations of longitudinal and transverse velocity structure functions using a vortex model of isotropic turbulence

    SciTech Connect

    He, G.; Doolen, G.D.; Chen, S.

    1999-12-01

    The longitudinal structure function (LSF) and the transverse structure function (TSF) in isotropic turbulence are calculated using a vortex model. The vortex model is composed of the Rankine and Burgers vortices which have the exponential distributions in the vortex Reynolds number and vortex radii. This model exhibits a power law in the inertial range and satisfies the minimal condition of isotropy that the second-order exponent of the LSF in the inertial range is equal to that of the TSF. Also observed are differences between longitudinal and transverse structure functions caused by intermittency. These differences are related to their scaling differences which have been previously observed in experiments and numerical simulations. {copyright} {ital 1999 American Institute of Physics.}

  4. Microwave measurements of energy lost to longitudinal modes by single electron bunches traversing periodic structures

    SciTech Connect

    Wang, J.W.; Loew, G.A.; Weaver, J.N.; Wilson, P.B.

    1981-10-01

    In the design of future linear colliders, it will be important to minimize the loss of beam energy due to the excitation of higher-order modes in the accelerator structure by single bunches of electrons or positrons. This loss is not only detrimental in itself but also gives rise to energy spectrum widening and transverse emittance growth. Microwave measurements made on disk-loaded and alternating-spoke structures to determine the loss to the longitudinal modes are described. In these measurements the Gaussian bunch is simulated by a current pulse of the same shape transmitted through the structure on an axial center conductor. Results to date are presented for the total longitudinal loss parameter per period K in volts per picocoulomb.

  5. Spin-Flop Transition and a Tilted Canted Spin Structure in a Coupled Antiferromagnet

    NASA Astrophysics Data System (ADS)

    Shimahara, Hiroshi; Ito, Kazuhiro

    2016-04-01

    We study a uniaxial coupled Heisenberg antiferromagnet that consists of two subsystems of classical spins with small and large lengths and spin-flop transitions in a magnetic field parallel to the magnetic easy axis. It is proved that the anisotropy of inter-subsystem coupling stabilizes an asymmetric canted antiferromagnetic phase with a tilted direction of antiferromagnetism that is not perpendicular to the magnetic field. In contrast to the conventional first-order spin-flop transition, the spin-flop transition from the Néel phase to such a tilted canted antiferromagnetic (TCAF) phase is of the second order in the absence of simple anisotropic energies in the subsystems. The transition from the TCAF phase to the high-field saturated spin phase is of the second order in the strong coupling limit of the exchange interactions J1 between the small spins, whereas when J1 is finite, it becomes first-order. Therefore, in the former case, the TCAF phase converts the Néel phase continuously into the saturated phase. The transitions to the TCAF phase are accompanied by additional spontaneous symmetry breaking, causing the uniform magnetization to have a nonzero component perpendicular to the magnetic field.

  6. Computational Electronic Structure of Photoinduced Spin Transitions in Molecular Photoswithches

    NASA Astrophysics Data System (ADS)

    Chachiyo, Teepanis

    2005-03-01

    Minimum Energy Crossing Points (MECPs) are the energy barriers associated with radiationless spin-crossover. Understanding the mechanisms of such spin-forbidden processes is of great fundamental and practical interest. Methods of locating MECPs have been developed by several authors with, in general, a poor convergence behavior which increases the computational cost. We present a new method based on spin density functional theory (SDFT) that exhibits fast logarithmic convergence and is suitable for large molecular systems. Spin photo-switchable compounds are becoming a growing area of research since, in principle, it is possible to exploit their spin degrees of freedom to store bits of information. For instance, the photoswitch [Fe(ptz)6](BF4)2;(ptz=1-propyltetrazole) has a singlet (S=0) ground state and, upon optical excitation, becomes trapped in a quintet state (S=2) as long as T < 50K. We applied our MECP methodology to study its geometrical and spin dynamics during spin crossover. Our results are useful for elucidating the geometric rearrangements and microscopic mechanisms that control the lifetime and the critical temperature of the meta-stable high spin (quintet) state. For example, the MECP-SDFT calculations showed that the transition from singlet ground state to a triplet ``intermediate'' state is accompanied by an unusually large 0.3å bond length elongation of the iron axial ligands.

  7. Spin-orbit coupling, electron transport and pairing instabilities in two-dimensional square structures

    NASA Astrophysics Data System (ADS)

    Kocharian, Armen N.; Fernando, Gayanath W.; Fang, Kun; Palandage, Kalum; Balatsky, Alexander V.

    2016-05-01

    Rashba spin-orbit effects and electron correlations in the two-dimensional cylindrical lattices of square geometries are assessed using mesoscopic two-, three- and four-leg ladder structures. Here the electron transport properties are systematically calculated by including the spin-orbit coupling in tight binding and Hubbard models threaded by a magnetic flux. These results highlight important aspects of possible symmetry breaking mechanisms in square ladder geometries driven by the combined effect of a magnetic gauge field spin-orbit interaction and temperature. The observed persistent current, spin and charge polarizations in the presence of spin-orbit coupling are driven by separation of electron and hole charges and opposite spins in real-space. The modeled spin-flip processes on the pairing mechanism induced by the spin-orbit coupling in assembled nanostructures (as arrays of clusters) engineered in various two-dimensional multi-leg structures provide an ideal playground for understanding spatial charge and spin density inhomogeneities leading to electron pairing and spontaneous phase separation instabilities in unconventional superconductors. Such studies also fall under the scope of current challenging problems in superconductivity and magnetism, topological insulators and spin dependent transport associated with numerous interfaces and heterostructures.

  8. /sup 13/C-/sup 13/C spin-spin coupling constants in structural investigations. II. Conformational structure of vinyl ethers

    SciTech Connect

    Krivdin, L.B.; Shcherbakov, V.V.; Bzhezovskii, V.M.; Kalabin, G.A.

    1986-10-10

    The /sup 13/C-/sup 13/C spin-spin coupling constants between the carbon nuclei of the vinyl group were measured for a series of vinyl ethers. It was established that the unshared electron pairs of the oxygen atom can make a substantial stereospecific contribution to the direct /sup 13/C-/sup 13/C constants of the adjacent nuclei. The observed effect was used to establish the conformational structure of the compounds.

  9. The impact of television viewing on brain structures: cross-sectional and longitudinal analyses.

    PubMed

    Takeuchi, Hikaru; Taki, Yasuyuki; Hashizume, Hiroshi; Asano, Kohei; Asano, Michiko; Sassa, Yuko; Yokota, Susumu; Kotozaki, Yuka; Nouchi, Rui; Kawashima, Ryuta

    2015-05-01

    Television (TV) viewing is known to affect children's verbal abilities and other physical, cognitive, and emotional development in psychological studies. However, the brain structural development associated with TV viewing has never been investigated. Here we examined cross-sectional correlations between the duration of TV viewing and regional gray/white matter volume (rGMV/rWMV) among 133 boys and 143 girls as well as correlations between the duration of TV viewing and longitudinal changes that occurred a few years later among 111 boys and 105 girls. After correcting for confounding factors, we found positive effects of TV viewing on rGMV of the frontopolar and medial prefrontal areas in cross-sectional and longitudinal analyses, positive effects of TV viewing on rGMV/rWMV of areas of the visual cortex in cross-sectional analyses, and positive effects of TV viewing on rGMV of the hypothalamus/septum and sensorimotor areas in longitudinal analyses. We also confirmed negative effects of TV viewing on verbal intelligence quotient (IQ) in cross-sectional and longitudinal analyses. These anatomical correlates may be linked to previously known effects of TV viewing on verbal competence, aggression, and physical activity. In particular, the present results showed effects of TV viewing on the frontopolar area of the brain, which has been associated with intellectual abilities. PMID:24256892

  10. Impact of reading habit on white matter structure: Cross-sectional and longitudinal analyses.

    PubMed

    Takeuchi, Hikaru; Taki, Yasuyuki; Hashizume, Hiroshi; Asano, Kohei; Asano, Michiko; Sassa, Yuko; Yokota, Susumu; Kotozaki, Yuka; Nouchi, Rui; Kawashima, Ryuta

    2016-06-01

    Psychological studies showed the quantity of reading habit affects the development of their reading skills, various language skills, and knowledge. However, despite a vast amount of literature, the effects of reading habit on the development of white matter (WM) structures critical to language and reading processes have never been investigated. In this study, we used the fractional anisotropy (FA) measure of diffusion tensor imaging to measure WM microstructural properties and examined cross-sectional and longitudinal correlations between reading habit and FA of the WM bundles in a large sample of normal children. In both cross-sectional and longitudinal analyses, we found that greater strength of reading habit positively affected FA in the left arcuate fasciculus (AF), in the left inferior fronto-occipital fasciculus (IFOF), and in the left posterior corona radiata (PCR). Consistent with previous studies, we also confirmed the significance or a tendency for positive correlation between the strength of reading habit and the Verbal Comprehension score in cross-sectional and longitudinal analyses. These cross-sectional and longitudinal findings indicate that a healthy reading habit may be directly or indirectly associated with the advanced development of WM critical to reading and language processes. Future intervention studies are needed to determine the causal effects of reading habits on WM in normal children. PMID:27033689