5,525,409 research outputs found

    Inversion phenomenon and phase diagram of the S=1/2S=1/2 distorted diamond chain with the XXZXXZ interaction anisotropy

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    We discuss the anisotropies of the Hamiltonian and the wave-function in an S=1/2S=1/2 distorted diamond chain. The ground-state phase diagram of this model is investigated using the degenerate perturbation theory up to the first order and the level spectroscopy analysis of the numerical diagonalization data. In some regions of the obtained phase diagram, the anisotropy of the Hamiltonian and that of the wave-function are inverted, which we call inversion phenomenon; the N\'{e}el phase appears for the XY-like anisotropy and the spin-fluid phase appears for the Ising-like anisotropy. Three key words are important for this nature, which are frustration, the trimer nature, and the XXZXXZ anisotropy.Comment: 4pages, 10 figures, for proceedings of SPQS 200

    Stability issues with baryons in AdS/CFT

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    We consider baryon vertices within the gauge/gravity correspondence for a class of curved backgrounds. The holographic description based on the N=4 SYM theory for SU(N) allows classical solutions representing bound states of k-quarks with k less than or equal to N. We construct the corresponding classical configurations and perform a stability analysis. We present the details for the theory at the conformal point and at finite temperature and show that there is a critical value of k, below which there is instability. This may also arise when the baryon reaches a critical size. We also extend our treatment to magnetically charged baryon vertices.Comment: v1: 22 Pages, 4 figures; v2: A reference corrected and a reference adde

    CMOL: Second Life for Silicon?

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    This report is a brief review of the recent work on architectures for the prospective hybrid CMOS/nanowire/ nanodevice ("CMOL") circuits including digital memories, reconfigurable Boolean-logic circuits, and mixed-signal neuromorphic networks. The basic idea of CMOL circuits is to combine the advantages of CMOS technology (including its flexibility and high fabrication yield) with the extremely high potential density of molecular-scale two-terminal nanodevices. Relatively large critical dimensions of CMOS components and the "bottom-up" approach to nanodevice fabrication may keep CMOL fabrication costs at affordable level. At the same time, the density of active devices in CMOL circuits may be as high as 1012 cm2 and that they may provide an unparalleled information processing performance, up to 1020 operations per cm2 per second, at manageable power consumption.Comment: Submitted on behalf of TIMA Editions (http://irevues.inist.fr/tima-editions

    Comment on Transverse Mass Dependence of Partonic Dilepton Production in Ultra-Relativistic Heavy Ion Collisions

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    Comment on scale breaking effects in dilepton emission from partons during the early stage of ultra-relativistic heavy ion collisionsComment: 6 pages, RevTe

    Determination of the Mott insulating transition by the multi-reference density functional theory

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    It is shown that a momentum-boost technique applied to the extended Kohn-Sham scheme enables the computational determination of the Mott insulating transition. Self-consistent solutions are given for correlated electron systems by the first-principles calculation defined by the multi-reference density functional theory, in which the effective short-range interaction can be determined by the fluctuation reference method. An extension of the Harriman construction is made for the twisted boundary condition in order to define the momentum-boost technique in the first-principles manner. For an effectively half-filled-band system, the momentum-boost method tells that the period of a metallic ground state by the LDA calculation is shortened to the least period of the insulating phase, indicating occurrence of the Mott insulating transition.Comment: 5 pages, 1 figure, to appear in J. Phys. Condens. Matte

    Some definition of the Artin exponent of finite groups

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    The Artin exponent induced from cyclic subgroups of finite groups was studied extensively by T.Y. Lam. A Burnside ring theoretic version of Lam's results for pp-groups was given by the author in an earlier paper. Here we look at the Artin exponent induced from the elementary abelian subgroups of finite pp-groups using some results of A. Dress

    On lacunary Toeplitz determinants

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    By using Riemann--Hilbert problem based techniques, we obtain the asymptotic expansion of lacunary Toeplitz determinants detN[camb[f]]\det_N\big[ c_{\ell_a-m_b}[f] \big] generated by holomorhpic symbols, where a=a\ell_a=a (resp. mb=bm_b=b) except for a finite subset of indices a=h1,,hna=h_1,\dots, h_n (resp. b=t1,,trb=t_1,\dots, t_r). In addition to the usual Szeg\"{o} asymptotics, our answer involves a determinant of size n+rn+r.Comment: 11 page

    New CLEO II Results on Charm Hadron Decays

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    We present new results on charm hadron decays from the CLEO II experiment. The D*+ width is measured for the first time, Gamma(D*+) = 96 +- 4 +- 22 keV. The semileptonic decay branching fractions are determined to be B(D+ --> Kbar*0 e+ nu_e) = (6.7 +- 0.4 +- 0.5 +- 0.4)% and B(D+ --> Kbar*0 mu+ nu_mu) = (6.5 +- 0.9 +- 0.5 +- 0.4)%. We observe evidence for Omega_c --> Omega- e+ nu_e and measure the product of the branching fraction and cross section, B(Omega_c --> Omega- e+ nu_e) x sigma(e+e- --> Omega_cX) = 42.2 +- 14.1 +- 11.9 fb. Within the framework of Heavy Quark Effective Theory, we measure in the decay Lambda+_c --> Lambda e+ nu_e the form factor ratio, R = f_2/f_1 = -0.31 +- 0.06 +- 0.06. This provides strong evidence that the form factor f_2 describing spin interactionof the s quark is non-zero. The Xi+_c lifetime is measured to be 503 +- 47 +- 18 fs. The results on branching fractions, cross section, and form factor ratio are preliminary.Comment: International Europhysics Conference on HEP, Budapest, 200
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