14,811 research outputs found

    Cross-Correlation analysis of WMAP and EGRET in Wavelet Space

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    We cross correlate the Wilkinson Microwave Anisotropy Probe (WMAP) first year data and the diffuse gamma-ray intensity maps from the Energetic Gamma Ray Experiment Telescope (EGRET) using spherical wavelet approaches. Correlations at 99.7% significance level have been detected, at scales around 15∘15^{\circ} in the WMAP foreground cleaned W-band and Q-band maps, based on data from regions that are outside the most conservative WMAP foreground mask; no significant correlation is found with the Tegmark cleaned map. The detected correlation is most likely of Galactic origin, and thus can help us probing the origins of possible Galactic foreground residuals and ultimately removing them from measured microwave sky maps.Comment: 4 pages, 7 figures; accepted for publication in ApJ

    The spacetime structure of MOND with Tully-Fisher relation and Lorentz invariance violation

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    It is believed that the modification of Newtonian dynamics (MOND) is possible alternate for dark matter hypothesis. Although Bekenstein's TeVeS supplies a relativistic version of MOND, one may still wish a more concise covariant formulism of MOND. In this paper, within covariant geometrical framwork, we present another version of MOND. We show the spacetime structure of MOND with properties of Tully-Fisher relation and Lorentz invariance violation.Comment: 6 pages. arXiv admin note: substantial text overlap with arXiv:1111.1383 and arXiv:1108.344

    Determination of the strong coupling gB∗Bπg_{B^* B\pi} from semi-leptonic B→πℓνB\to \pi \ell \nu decay

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    According to heavy-meson chiral perturbation theory, the vector form factor f+(q2)f_+(q^2) of exclusive semi-leptonic decay B→πℓνB\to \pi \ell \nu is closely related, at least in the soft-pion region (i.e., q2∼(mB−mπ)2q^{2} \sim (m_B-m_{\pi})^2), to the strong coupling gB∗Bπg_{B^* B\pi} or the normalized coupling g^\hat g. Combining the precisely measured q2q^2 spectrum of B→πℓνB\to \pi \ell \nu decay by the BaBar and Belle collaborations with several parametrizations of the form factor f+(q2)f_+(q^2), we can extract these couplings from the residue of the form factor at the B∗B^* pole, which relies on an extrapolation of the form factor from the semi-leptonic region to the unphysical point q2=mB∗2q^2=m_{B^*}^2. Comparing the extracted values with the other experimental and theoretical estimates, we can test these various form-factor parametrizations, which differ from each other by the amount of physical information embedded in. It is found that the extracted values based on the BK, BZ and BCL parametrizations are consistent with each other and roughly in agreement with the other theoretical and lattice estimates, while the BGL ansatz, featured by a spurious, unwanted pole at the threshold of the cut, gives a neatly larger value.Comment: 19 pages, no figure. Revise

    Classification of GHZ-type, W-type and GHZ-W-type multiqubit entanglements

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    We propose the concept of SLOCC-equivalent basis (SEB) in the multiqubit space. In particular, two special SEBs, the GHZ-type and the W-type basis are introduced. They can make up a more general family of multiqubit states, the GHZ-W-type states, which is a useful kind of entanglement for quantum teleporatation and error correction. We completely characterize the property of this type of states, and mainly classify the GHZ-type states and the W-type states in a regular way, which is related to the enumerative combinatorics. Many concrete examples are given to exhibit how our method is used for the classification of these entangled states.Comment: 16 pages, Revte

    Theoretical Study on Rotational Bands and Shape Coexistence of 183,185,187^{183,185,187}{Tl} in the Particle Triaxial-Rotor Model

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    By taking the particle triaxial-rotor model with variable moment of inertia, we investigate the energy spectra, the deformations and the single particle configurations of the nuclei 183,185,187^{183,185,187}Tl systemically. The calculated energy spectra agree with experimental data quite well. The obtained results indicate that the aligned bands observed in 183,185,187^{183,185,187}Tl originate from the [530]1/2−[530]{{1/2}}^{-}, [532]3/2−[532]{{3/2}}^{-}, [660]1/2+[660]{{1/2}}^{+} proton configuration coupled to a prolate deformed core, respectively. Whereas, the negative parity bands built upon the 9/2−{{9/2}}^{-} isomeric states in 183,185,187^{183,185,187}Tl are formed by a proton with the [505]9/2−[505]{{9/2}}^{-} configuration coupled to a core with triaxial oblate deformation, and the positive parity band on the 13/2+{{13/2}}^{+} isomeric state in 187^{187}Tl is generated by a proton with configuration [606]13/2+[606]{{13/2}}^{+} coupled to a triaxial oblate core.Comment: 16 pages, 5 figures. To appear in Physical Review

    Comparison of Power Dependence of Microwave Surface Resistance of Unpatterned and Patterned YBCO Thin Film

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    The effect of the patterning process on the nonlinearity of the microwave surface resistance RSR_S of YBCO thin films is investigated. With the use of a sapphire dielectric resonator and a stripline resonator, the microwave RSR_S of YBCO thin films was measured before and after the patterning process, as a function of temperature and the rf peak magnetic field in the film. The microwave loss was also modeled, assuming a Jrf2J_{rf}^2 dependence of ZS(Jrf)Z_S(J_{rf}) on current density JrfJ_{rf}. Experimental and modeled results show that the patterning has no observable effect on the microwave residual RSR_S or on the power dependence of RSR_S.Comment: Submitted to IEEE Trans. MT

    Tunneling Qubit Operation on a Protected Josephson Junction Array

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    We discuss a protected quantum computation process based on a hexagon Josephson junction array. Qubits are encoded in the punctured array, which is topologically protected. The degeneracy is related to the number of holes. The topological degeneracy is lightly shifted by tuning the flux through specific hexagons. We also show how to perform single qubit operation and basic quantum gate operations in this system.Comment: 8 pages, 4 figures. The published version in Phys. Rev., A81(2010)01232
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