123,608 research outputs found

    Thermal fluctuations and anomalous elasticity of homogeneous nematic elastomers

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    We present a unified formulation of a rotationally invariant nonlinear elasticity for a variety of spontaneously anisotropic phases, and use it to study thermal fluctuations in nematic elastomers and spontaneously anisotropic gels. We find that in a thermodynamic limit homogeneous nematic elastomers are universally incompressible, are characterized by a universal ratio of shear moduli, and exhibit an anomalous elasticity controlled by a nontrivial low temperature fixed point perturbative in D=3-epsilon dimensions. In three dimensions, we make predictions that are asymptotically exact.Comment: 4 RevTeX pgs,,submitted to Europhysics Letter

    New Time Distributions of D^0-\bar{D}^0 or B^0-\bar{B}^0 Mixing and CP Violation

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    The formulae for D^0-\bar{D}^0 or B^0-\bar{B}^0 mixing and CP violation at the \tau-charm or B-meson factories are derived, for the case that only the decay-time distribution of one D or B meson is to be measured. In particular, we point out a new possibility to determine the D^0-\bar{D}^0 mixing rate in semileptonic D decays at the \Psi (4.14) resonance; and show that both direct and indirect CP asymmetries can be measured at the \Upsilon (4S) resonance without ordering the decay times of two B_d mesons or measuring their difference.Comment: LaTex 10 pages (3 figures). Phys. Lett. B (in printing

    Lepton Mass Hierarchy and Neutrino Mixing

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    We speculate that the mass spectrum of three neutrinos might have a normal hierarchy as that of three charged leptons or that of three up-type (or down-type) quarks. In this spirit, we propose a novel parametrization of the 3×33\times 3 lepton flavor mixing matrix. Its mixing angles θl\theta_l and θν\theta_\nu can be related to the mass ratios me/mμm_e/m_\mu and m1/m2m_1/m_2 in a specific texture of lepton mass matrices with vanishing (1,1) elements: tanθl=me/mμ\tan\theta_l = \sqrt{m_e/m_\mu} and tanθν=m1/m2\tan\theta_\nu = \sqrt{m_1/m_2}. The latter relation, together with solar and atmospheric neutrino oscillation data, predicts 0.0030 eV m1\lesssim m_1 \lesssim 0.0073 eV, 0.009 eV m2\lesssim m_2 \lesssim 0.012 eV and 0.042 eV m3\lesssim m_3 \lesssim 0.058 eV. The smallest neutrino mixing angle is found to be θ13θl/23\theta_{13} \approx \theta_l/\sqrt{2} \approx 3^\circ, which is experimentally accessible in the near future.Comment: RevTex 10 pages, 2 figure
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