34,447 research outputs found

    On the Application of Gluon to Heavy Quarkonium Fragmentation Functions

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    We analyze the uncertainties induced by different definitions of the momentum fraction zz in the application of gluon to heavy quarkonium fragmentation function. We numerically calculate the initial gJ/ψg \to J / \psi fragmentation functions by using the non-covariant definitions of zz with finite gluon momentum and find that these fragmentation functions have strong dependence on the gluon momentum k\vec{k}. As k| \vec{k} | \to \infty, these fragmentation functions approach to the fragmentation function in the light-cone definition. Our numerical results show that large uncertainties remains while the non-covariant definitions of zz are employed in the application of the fragmentation functions. We present for the first time the polarized gluon to J/ψJ/\psi fragmentation functions, which are fitted by the scheme exploited in this work.Comment: 11 pages, 7 figures;added reference for sec.

    Recycle-GAN: Unsupervised Video Retargeting

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    We introduce a data-driven approach for unsupervised video retargeting that translates content from one domain to another while preserving the style native to a domain, i.e., if contents of John Oliver's speech were to be transferred to Stephen Colbert, then the generated content/speech should be in Stephen Colbert's style. Our approach combines both spatial and temporal information along with adversarial losses for content translation and style preservation. In this work, we first study the advantages of using spatiotemporal constraints over spatial constraints for effective retargeting. We then demonstrate the proposed approach for the problems where information in both space and time matters such as face-to-face translation, flower-to-flower, wind and cloud synthesis, sunrise and sunset.Comment: ECCV 2018; Please refer to project webpage for videos - http://www.cs.cmu.edu/~aayushb/Recycle-GA

    Competition of different coupling schemes in atomic nuclei

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    Shell model calculations reveal that the ground and low-lying yrast states of the N=ZN=Z nuclei 4692^{92}_{46}Pd and 96^{96}Cd are mainly built upon isoscalar spin-aligned neutron-proton pairs each carrying the maximum angular momentum J=9 allowed by the shell 0g9/20g_{9/2} which is dominant in this nuclear region. This mode of excitation is unique in nuclei and indicates that the spin-aligned pair has to be considered as an essential building block in nuclear structure calculations. In this contribution we will discuss this neutron-proton pair coupling scheme in detail. In particular, we will explore the competition between the normal monopole pair coupling and the spin-aligned coupling schemes. Such a coupling may be useful in elucidating the structure properties of N=ZN=Z and neighboring nuclei.Comment: 10 pages, 7 figures, 1 table. Proceedings of the Conference on Advanced Many-Body and Statistical Methods in Mesoscopic Systems, Constanta, Romania, June 27th - July 2nd 2011. To appear in Journal of Physics: Conference Serie

    Exploring DCO+^+ as a tracer of thermal inversion in the disk around the Herbig Ae star HD163296

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    We aim to reproduce the DCO+^+ emission in the disk around HD163296 using a simple 2D chemical model for the formation of DCO+^+ through the cold deuteration channel and a parametric treatment of the warm deuteration channel. We use data from ALMA in band 6 to obtain a resolved spectral imaging data cube of the DCO+^+ JJ=3--2 line in HD163296 with a synthesized beam of 0."53×\times 0."42. We adopt a physical structure of the disk from the literature that reproduces the spectral energy distribution. We then apply a simplified chemical network for the formation of DCO+^+ that uses the physical structure of the disk as parameters along with a CO abundance profile, a constant HD abundance and a constant ionization rate. Finally, from the resulting DCO+^+ abundances, we calculate the non-LTE emission using the 3D radiative transfer code LIME. The observed DCO+^+ emission is reproduced by a model with cold deuteration producing abundances up to 1.6×10111.6\times 10^{-11}. Warm deuteration, at a constant abundance of 3.2×10123.2\times 10^{-12}, becomes fully effective below 32 K and tapers off at higher temperatures, reproducing the lack of DCO+^+ inside 90 AU. Throughout the DCO+^+ emitting zone a CO abundance of 2×1072\times 10^{-7} is found, with \sim99\% of it frozen out below 19 K. At radii where both cold and warm deuteration are active, warm deuteration contributes up to 20\% of DCO+^+, consistent with detailed chemical models. The decrease of DCO+^+ at large radii is attributed to a temperature inversion at 250 AU, which raises temperatures above values where cold deuteration operates. Increased photodesorption may also limit the radial extent of DCO+^+. The corresponding return of the DCO+^+ layer to the midplane, together with a radially increasing ionization fraction, reproduces the local DCO+^+ emission maximum at \sim260 AU.Comment: 9 pages, 5 figures, accepted 7th July 201

    Multistep shell model in the complex energy plane

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    We have adopted the multistep shell model in the complex energy plane to study nuclear excitations occurring in the continuum part of the spectrum. In this method one proceeds by solving the shell model equations in a successive manner. That is, in each step one constructs the building blocks to be used in future steps. We applied this formalism to analyze the unbound nuclei 12,13^{12,13}Li starting from the one-particle states in 10^{10}Li and two-particle states in 11^{11}Li. In the former case the excitations correspond to the motion of three particles partitioned as the product of a one-particle and two-particle systems. The ground state of 12^{12}Li is thus calculated to be an antibound (virtual) state. In the four-particle system 13^{13}Li the states can be constructed as the coupling of two correlated pairs. We found that there is no bound or antibound state in 13^{13}Li.Comment: 10 pages, 2 table, 3 figures, Proceedings of the Conference on Advanced Many-Body and Statistical Methods in Mesoscopic Systems, Constanta, Romania, June 27th - July 2nd 2011. To appear in Journal of Physics: Conference Serie

    Strangeness spin, magnetic moment and strangeness configurations of the proton

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    The implications of the empirical signatures for the positivity of the strangeness magnetic moment μs\mu_s, and the negativity of the strangeness contribution to the proton spin Δs\Delta_s, on the possible uudssˉuuds\bar s configurations of five quarks in the proton are analyzed. The empirical signs for the values of these two observables can only be obtained in configurations where the uudsuuds system is orbitally excited and the sˉ\bar s quark is in the ground state. The configurations, in which the sˉ\bar s is orbitally excited, which include the conventional K+Λ0K^+\Lambda^0 congfiguration, with the exception of that, in which the uudsuuds component has spin 2, yield negative values for μs\mu_s. Here the strangeness spin Δs\Delta_s, the strangeness magnetic moment μs\mu_s and the axial coupling constant GAsG_A^s are calculated for all possible configurations of the uudssˉuuds\bar s component of the proton. In the configuration with [4]FS[22]F[22]S[4]_{FS}[22]_F[22]_S flavor-spin symmetry, which is likely to have the lowest energy, μs\mu_s is positive and ΔsGAs1/3μs\Delta_s\simeq G_A^s\simeq -1/3\mu_s.Comment: 17 page

    Universal scattering behavior of co-assembled nanoparticle-polymer clusters

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    Water-soluble clusters made from 7 nm inorganic nanoparticles have been investigated by small-angle neutron scattering. The internal structure factor of the clusters was derived and exhibited a universal behavior as evidenced by a correlation hole at intermediate wave-vectors. Reverse Monte-Carlo calculations were performed to adjust the data and provided an accurate description of the clusters in terms of interparticle distance and volume fraction. Additional parameters influencing the microstructure were also investigated, including the nature and thickness of the nanoparticle adlayer.Comment: 5 pages, 4 figures, paper published in Physical Review
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