68,559 research outputs found

    The NLO QCD Corrections to BcB_c Meson Production in Z0Z^0 Decays

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    The decay width of Z0Z^0 to BcB_c meson is evaluated at the next-to-leading order(NLO) accuracy in strong interaction. Numerical calculation shows that the NLO correction to this process is remarkable. The quantum chromodynamics(QCD)renormalization scale dependence of the results is obviously depressed, and hence the uncertainties lying in the leading order calculation are reduced.Comment: 14 pages, 7 figures; references added; expressions and typos ammende

    Modeling and Analysis of Power Processing Systems (MAPPS). Volume 2: Appendices

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    The computer programs and derivations generated in support of the modeling and design optimization program are presented. Programs for the buck regulator, boost regulator, and buck-boost regulator are described. The computer program for the design optimization calculations is presented. Constraints for the boost and buck-boost converter were derived. Derivations of state-space equations and transfer functions are presented. Computer lists for the converters are presented, and the input parameters justified

    Arbitrary Dimensional Schwarzschild-FRW Black Holes

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    The metric of arbitrary dimensional Schwarzschild black hole in the background of Friedman-Robertson-Walker universe is presented in the cosmic coordinates system. In particular, the arbitrary dimensional Schwarzschild-de Sitter metric is rewritten in the Schwarzschild coordinates system and basing on which the even more generalized higher dimensional Schwarzschild-de Sitter metric with another extra dimensions is found. The generalized solution shows that the cosmological constant may roots in the extra dimensions of space.Comment: 10 page

    Radiolabeling human peripheral blood stem cells for positron emission tomography (PET) imaging in young rhesus monkeys.

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    These studies focused on a new radiolabeling technique with copper ((64)Cu) and zirconium ((89)Zr) for positron emission tomography (PET) imaging using a CD45 antibody. Synthesis of (64)Cu-CD45 and (89)Zr-CD45 immunoconjugates was performed and the evaluation of the potential toxicity of radiolabeling human peripheral blood stem cells (hPBSC) was assessed in vitro (viability, population doubling times, colony forming units). hPBSC viability was maintained as the dose of (64)Cu-TETA-CD45 increased from 0 (92%) to 160 µCi/mL (76%, p>0.05). Radiolabeling efficiency was not significantly increased with concentrations of (64)Cu-TETA-CD45 >20 µCi/mL (p>0.50). Toxicity affecting both growth and colony formation was observed with hPBSC radiolabeled with ≥40 µCi/mL (p<0.05). For (89)Zr, there were no significant differences in viability (p>0.05), and a trend towards increased radiolabeling efficiency was noted as the dose of (89)Zr-Df-CD45 increased, with a greater level of radiolabeling with 160 µCi/mL compared to 0-40 µCi/mL (p<0.05). A greater than 2,000 fold-increase in the level of (89)Zr-Df-CD45 labeling efficiency was observed when compared to (64)Cu-TETA-CD45. Similar to (64)Cu-TETA-CD45, toxicity was noted when hPBSC were radiolabeled with ≥40 µCi/mL (p<0.05) (growth, colony formation). Taken together, 20 µCi/mL resulted in the highest level of radiolabeling efficiency without altering cell function. Young rhesus monkeys that had been transplanted prenatally with 25×10(6) hPBSC expressing firefly luciferase were assessed with bioluminescence imaging (BLI), then 0.3 mCi of (89)Zr-Df-CD45, which showed the best radiolabeling efficiency, was injected intravenously for PET imaging. Results suggest that (89)Zr-Df-CD45 was able to identify engrafted hPBSC in the same locations identified by BLI, although the background was high

    Modeling and Analysis of Power Processing Systems (MAPPS). Volume 1: Technical report

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    Computer aided design and analysis techniques were applied to power processing equipment. Topics covered include: (1) discrete time domain analysis of switching regulators for performance analysis; (2) design optimization of power converters using augmented Lagrangian penalty function technique; (3) investigation of current-injected multiloop controlled switching regulators; and (4) application of optimization for Navy VSTOL energy power system. The generation of the mathematical models and the development and application of computer aided design techniques to solve the different mathematical models are discussed. Recommendations are made for future work that would enhance the application of the computer aided design techniques for power processing systems

    Exact Potts Model Partition Functions for Strips of the Honeycomb Lattice

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    We present exact calculations of the Potts model partition function Z(G,q,v)Z(G,q,v) for arbitrary qq and temperature-like variable vv on nn-vertex strip graphs GG of the honeycomb lattice for a variety of transverse widths equal to LyL_y vertices and for arbitrarily great length, with free longitudinal boundary conditions and free and periodic transverse boundary conditions. These partition functions have the form Z(G,q,v)=∑j=1NZ,G,λcZ,G,j(λZ,G,j)mZ(G,q,v)=\sum_{j=1}^{N_{Z,G,\lambda}} c_{Z,G,j}(\lambda_{Z,G,j})^m, where mm denotes the number of repeated subgraphs in the longitudinal direction. We give general formulas for NZ,G,jN_{Z,G,j} for arbitrary LyL_y. We also present plots of zeros of the partition function in the qq plane for various values of vv and in the vv plane for various values of qq. Explicit results for partition functions are given in the text for Ly=2,3L_y=2,3 (free) and Ly=4L_y=4 (cylindrical), and plots of partition function zeros are given for LyL_y up to 5 (free) and Ly=6L_y=6 (cylindrical). Plots of the internal energy and specific heat per site for infinite-length strips are also presented.Comment: 39 pages, 34 eps figures, 3 sty file

    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 g→J/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 k⃗\vec{k}. As ∣k⃗∣→∞| \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.

    Estimating Form Factors of Bs→Ds(∗)B_s\rightarrow D_s^{(*)} and their Applications to Semi-leptonic and Non-leptonic Decays

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    Bs0→Ds−B_s^0\rightarrow D_s^{-} and Bs0→Ds∗−B_s^0\rightarrow D_s^{*-} weak transition form factors are estimated for the whole physical region with a method based on an instantaneous approximated Mandelstam formulation of transition matrix elements and the instantaneous Bethe-Salpeter equation. We apply the estimated form factors to branching ratios, CP asymmetries and polarization fractions of non-leptonic decays within the factorization approximation. And we study the non-factorizable effects and annihilation contributions with the perturbative QCD approach. The branching ratios of semi-leptonic Bs0→Ds(∗)−l+νlB_s^0\rightarrow D_s^{(*)-}l^+\nu_l decays are also evaluated. We show that the calculated decay rates agree well with the available experimental data. The longitudinal polarization fraction of Bs→Ds∗V(A)B_s\rightarrow D_s^*V(A) decays are ∼0.8\sim0.8 when V(A)V(A) denotes a light meson, and are ∼0.5\sim0.5 when V(A)V(A) denotes a DqD_q (q=d,sq=d,s) meson.Comment: Final version published in J Phys. G 39 (2012) 045002 (Title also changed
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