2,347 research outputs found

    Collins effect in semi-inclusive deep inelastic scattering process with a 3^3He target

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    We re-examine our previous calculation on the Collins effect in semi-inclusive deeply inelastic scattering (SIDIS) process with a 3^3He target, and find that our previous treatment on the dilution factors may cause the results larger than the realistic situation. We thus modify our calculation in an improved treatment with an updated prediction on the sin(ϕh+ϕS)\sin(\phi_h+\phi_S) asymmetry for the JLab 12 GeV under the transverse momentum dependent (TMD) factorization framework. Meanwhile, we also provide the prediction of such asymmetry for the JLab 6 GeV and the prediction of the sin(3ϕhϕS)\sin(3\phi_h-\phi_S) asymmetry related to pretzelosity.Comment: 10 pages, 4 figures, figures 3 and 4 replaced as Erratu

    The sin2ϕ\sin2\phi azimuthal asymmetry in single longitudinally polarized πN\pi N Drell-Yan process

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    We study the sin2ϕ\sin2\phi azimuthal asymmetry in the πN\pi N Drell-Yan process, when the nucleon is longitudinally polarized. The asymmetry is contributed by the combination of the Boer-Mulders function and the longitudinal transversity distribution function. We consider the Drell-Yan processes by π±\pi^\pm beams colliding on the proton and deuteron targets, respectively. We calculate the sin2ϕ\sin2\phi azimuthal asymmetries in these processes using the Boer-Mulders function and the longitudinal transversity from spectator models. We show that the study on single polarized πN\pi N Drell-Yan processes can not only give the information on the new 3-dimensional parton distribution functions in momentum space, but also shed light on the chiral-odd structure of the longitudinally polarized nucleon.Comment: 7 pages, 3 figures. Final version for publication in PR

    Transversity from two pion interference fragmentation

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    We present calculation on the azimuthal spin asymmetries for pion pair production in semi-inclusive deep inelastic scattering (SIDIS) process at both HERMES and COMPASS kinematics, with transversely polarized proton, deuteron and neutron targets. We calculate the asymmetry by adopting a set of parametrization of the interference fragmentation functions and two different models for the transversity. We find that the result for the proton target is insensitive to the approaches of the transversity but more helpful to understand the interference fragmentation functions. However, for the neutron target, which can be obtained through using deuteron and {3^3He} targets, we find different predictions for different approaches to the transversity. Thus probing the two pion interference fragmentation from the neutron can provide us more interesting information on the transversity.Comment: 15 latex pages, 6 figures, to appear in PR

    Pretzelosity h1Th_{1T}^{\perp} and quark orbital angular momentum

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    We calculate the pretzelosity distribution (h1Th_{1T}^{\perp}), which is one of the eight leading twist transverse momentum dependent parton distributions (TMDs), in the light-cone formalism. We find that this quantity has a simple relation with the quark orbital angular momentum distribution, thus it may provide a new possibility to access the quark orbital angular momentum inside the nucleon. The pretzelosity distribution can manifest itself through the sin(3ϕhϕS)\sin(3\phi_h-\phi_S) asymmetry in semi-inclusive deep inelastic scattering process. We calculate the sin(3ϕhϕS)\sin(3\phi_h-\phi_S) asymmetry at HERMES, COMPASS and JLab kinematics, and present our prediction on different targets including the proton, deuteron and neutron targets. Inclusion of transverse momentum cut in data analysis could significantly enhance the sin(3ϕhϕS)\sin(3\phi_h-\phi_S) asymmetry for future measurements.Comment: 20 latex pages, 7 figures, to appear in PR

    Device modeling of superconductor transition edge sensors based on the two-fluid theory

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    In order to support the design and study of sophisticated large scale transition edge sensor (TES) circuits, we use basic SPICE elements to develop device models for TESs based on the superfluid-normal fluid theory. In contrast to previous studies, our device model is not limited to small signal simulation, and it relies only on device parameters that have clear physical meaning and can be easily measured. We integrate the device models in design kits based on powerful EDA tools such as CADENCE and OrCAD, and use them for versatile simulations of TES circuits. Comparing our simulation results with published experimental data, we find good agreement which suggests that device models based on the two-fluid theory can be used to predict the behavior of TES circuits reliably and hence they are valuable for assisting the design of sophisticated TES circuits.Comment: 10pages,11figures. Accepted to IEEE Trans. Appl. Supercon

    Realization of Zero-Refractive-Index Lens with Ultralow Spherical Aberration

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    Optical complex materials offer unprecedented opportunity to engineer fundamental band dispersion which enables novel optoelectronic functionality and devices. Exploration of photonic Dirac cone at the center of momentum space has inspired an exceptional characteristic of zero-index, which is similar to zero effective mass in fermionic Dirac systems. Such all-dielectric zero-index photonic crystals provide an in-plane mechanism such that the energy of the propagating waves can be well confined along the chip direction. A straightforward example is to achieve the anomalous focusing effect without longitudinal spherical aberration, when the size of zero-index lens is large enough. Here, we designed and fabricated a prototype of zero-refractive-index lens by comprising large-area silicon nanopillar array with plane-concave profile. Near-zero refractive index was quantitatively measured near 1.55 um through anomalous focusing effect, predictable by effective medium theory. The zero-index lens was also demonstrated to perform ultralow longitudinal spherical aberration. Such IC compatible device provides a new route to integrate all-silicon zero-index materials into optical communication, sensing, and modulation, and to study fundamental physics on the emergent fields of topological photonics and valley photonics.Comment: 14 pages, 4 figure
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