6,881 research outputs found

    Updates of WRW_R effects on CP angles determination in B decays

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    The recently observed CP violation in B decay and BB-\ovar{B} mixing data put constraints on the mass of WRW_R and the parameters of the right-handed current quark mixing matrix VRV^R in SU(2)L×SU(2)R×U(1)SU(2)_L \times SU(2)_R\times U(1) gauge model. It is shown that the allowed region of parameters are severely restricted for light WRW_R with mass on the order of 1 TeV. There exist sets of parameters which can accommodate large CP violation as measured by Belle, sin2ϕ1exp1\sin2\phi_1|_{exp}\simeq 1, for MWR=110M_{W_R}=1 \sim 10 TeV.Comment: 11pages, 19 figures, LaTeX2

    Hydrodynamic Description of Granular Convection

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    We present a hydrodynamic model that captures the essence of granular dynamics in a vibrating bed. We carry out the linear stability analysis and uncover the instability mechanism that leads to the appearance of the convective rolls via a supercritical bifurcation of a bouncing solution. We also explicitly determine the onset of convection as a function of control parameters and confirm our picture by numerical simulations of the continuum equations.Comment: 14 pages, RevTex 11pages + 3 pages figures (Type csh

    Condensation of Hard Spheres Under Gravity: Exact Results in One Dimension

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    We present exact results for the density profile of the one dimensional array of N hard spheres of diameter D and mass m under gravity g. For a strictly one dimensional system, the liquid-solid transition occurs at zero temperature, because the close-pakced density, ϕc\phi_c, is one. However, if we relax this condition slightly such that phic=1δphi_c=1-\delta, we find a series of critical temperatures T_c^i=mgD(N+1-i)/\mu_o with \mu_o=const, at which the i-th particle undergoes the liquid-solid transition. The functional form of the onset temperature, T_c^1=mgDN/\mu_o, is consistent with the previous result [Physica A 271, 192 (1999)] obtained by the Enskog equation. We also show that the increase in the center of mass is linear in T before the transition, but it becomes quadratic in T after the transition because of the formation of solid near the bottom

    Geometrical Pumping in Quantum Transport: Quantum Master Equation Approach

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    For an open quantum system, we investigate the pumped current induced by a slow modulation of control parameters on the basis of the quantum master equation and full counting statistics. We find that the average and the cumulant generating function of the pumped quantity are characterized by the geometrical Berry-phase-like quantities in the parameter space, which is associated with the generator of the master equation. From our formulation, we can discuss the geometrical pumping under the control of the chemical potentials and temperatures of reservoirs. We demonstrate the formulation by spinless electrons in coupled quantum dots. We show that the geometrical pumping is prohibited for the case of non-interacting electrons if we modulate only temperatures and chemical potentials of reservoirs, while the geometrical pumping occurs in the presence of an interaction between electrons

    Tenth-Order QED Contribution to the Electron g-2 and an Improved Value of the Fine Structure Constant

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    This paper presents the complete QED contribution to the electron g-2 up to the tenth order. With the help of the automatic code generator, we have evaluated all 12672 diagrams of the tenth-order diagrams and obtained 9.16 (58)(\alpha/\pi)^5. We have also improved the eighth-order contribution obtaining -1.9097(20)(\alpha/\pi)^4, which includes the mass-dependent contributions. These results lead to a_e(theory)=1 159 652 181.78 (77) \times 10^{-12}. The improved value of the fine-structure constant \alpha^{-1} = 137.035 999 174 (35) [0.25 ppb] is also derived from the theory and measurement of a_e.Comment: 4 pages, 2 figures. Some numbers are slightly change

    Collision of One-Dimensional Nonlinear Chains

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    We investigate one-dimensional collisions of unharmonic chains and a rigid wall. We find that the coefficient of restitution (COR) is strongly dependent on the velocity of colliding chains and has a minimum value at a certain velocity. The relationship between COR and collision velocity is derived for low-velocity collisions using perturbation methods. We found that the velocity dependence is characterized by the exponent of the lowest unharmonic term of interparticle potential energy
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