13,340 research outputs found

    The virtual human face – superimposing the simultaneously captured 3D photorealistic skin surface of the face on the untextured skin image of the CBCT Scan

    Get PDF
    The aim of this study was to evaluate the impact of simultaneous capture of the three-dimensional (3D) surface of the face and cone beam computed tomography (CBCT) scan of the skull on the accuracy of their registration and superimposition. 3D facial images were acquired in 14 patients using the Di3d (Dimensional Imaging, UK) imaging system and i-CAT CBCT scanner. One stereophotogrammetry image was captured at the same time as the CBCT and another one hour later. The two stereophotographs were then individually superimposed over the CBCT using VRmesh. Seven patches were isolated on the final merged surfaces. For the whole face and each individual patch; maximum and minimum range of deviation between surfaces, absolute average distance between surfaces, and standard deviation for the 90th percentile of the distance errors were calculated. The superimposition errors of the whole face for both captures revealed statistically significant differences (P=0.00081). The absolute average distances in both separate and simultaneous captures were 0.47mm and 0.27mm, respectively. The level of superimposition accuracy in patches from separate captures ranged between 0.3 and 0.9mm, while that of simultaneous captures was 0.4mm. Simultaneous capture of Di3d and CBCT images significantly improved the accuracy of superimposition of these image modalities

    EM Decay of X(3872) as the 11D2(2−+)1{^1D_2}(2^{-+}) charmonium

    Full text link
    The recently BaBar results raise the possibility that X(3872) has negative parity. This makes people reconsider assigning X(3872) to the 11D2(ccˉ)1{^1D_2}(c\bar c) state. In this paper we give a general form of the wave function of 2−+2^{-+} mesons. By solving the instantaneous Bethe-Salpeter equation, we get the mass spectrum and corresponding wave functions. We calculate electromagnetic decay widths of the first 2−+2^{-+} state which we assume to be the X(3872) particle. The results are Γ(2−+(3872)→J/ψγ)=1.59−0.42+0.53\Gamma(2^{-+}(3872)\rightarrow J/\psi\gamma) = 1.59^{+0.53}_{-0.42} keV, Γ(2−+(3872)→ψ(2S)γ)=2.87−0.97+1.46\Gamma(2^{-+}(3872)\rightarrow \psi(2S)\gamma) = 2.87^{+1.46}_{-0.97} eV and Γ(2−+(3872)→ψ(3770)γ)=0.135−0.047+0.066\Gamma(2^{-+}(3872)\rightarrow \psi(3770)\gamma) = 0.135^{+0.066}_{-0.047} keV. The ratio of branch fractions of the second and first channel is about 0.002, which is inconsistent with the experimental value 3.4±1.43.4\pm 1.4. So X(3872) is unlikely to be a 2−+2^{-+} charmonium state. In addition, we obtain a relatively large decay width for 2−+(3872)→hcγ2^{-+}(3872)\rightarrow h_c\gamma channel which is 392−111+62392^{+62}_{-111} keV.Comment: Revised versio

    Super Yangian Double DY(gl(1∣1))DY( gl(1|1)) and Its Gauss Decomposition

    Full text link
    We extend Yangian double to super (or graded) case and give its Drinfel'd generators realization by Gauss decomposition.Comment: 6 pages, Latex, no figure

    Amplitude Damping for single-qubit System with single-qubit mixed-state Environment

    Full text link
    We study a generalized amplitude damping channel when environment is initially in the single-qubit mixed state. Representing the affine transformation of the generalized amplitude damping by a three-dimensional volume, we plot explicitly the volume occupied by the channels simulatable by a single-qubit mixed-state environment. As expected, this volume is embedded in the total volume by the channels which is simulated by two-qubit enviroment. The volume ratio is approximately 0.08 which is much smaller than 3/8, the volume ratio for generalized depolarizing channels.Comment: 13 pages, 2 figures incluided V2: homepage address is included in reference V3: version to appear in J. Phys. A: Mathematical and Theoretica

    Boundary K-matrices and the Lax pair for 1D open XYZ spin-chain

    Full text link
    We analysis the symmetries of the reflection equation for open XYZXYZ model and find their solutions K±K^{\pm} case by case. In the general open boundary conditions, the Lax pair for open one-dimensional XYZXYZ spin-chain is given.Comment: LaTeX, 17 pages, errors in references correcte

    Super-Yangian Y(gl(1|1)) and Its Oscillator Realization

    Get PDF
    On the basis of graded RTT formalism,the defining relation of the super-Yangian Y(gl(1|1)) is derived and its oscillator realization is constructed.Comment: 7 pages, latex, no figures, to appaer in the International Workshop on Frontiers in Quantum Field Theory,Urumqi,11-18,Augast,199

    Translation Representations and Scattering By Two Intervals

    Get PDF
    Studying unitary one-parameter groups in Hilbert space (U(t),H), we show that a model for obstacle scattering can be built, up to unitary equivalence, with the use of translation representations for L2-functions in the complement of two finite and disjoint intervals. The model encompasses a family of systems (U (t), H). For each, we obtain a detailed spectral representation, and we compute the scattering operator, and scattering matrix. We illustrate our results in the Lax-Phillips model where (U (t), H) represents an acoustic wave equation in an exterior domain; and in quantum tunneling for dynamics of quantum states
    • …
    corecore