6,881 research outputs found
Updates of effects on CP angles determination in B decays
The recently observed CP violation in B decay and -\ovar{B} mixing data
put constraints on the mass of and the parameters of the right-handed
current quark mixing matrix in gauge
model. It is shown that the allowed region of parameters are severely
restricted for light with mass on the order of 1 TeV. There exist sets of
parameters which can accommodate large CP violation as measured by Belle,
, for TeV.Comment: 11pages, 19 figures, LaTeX2
Hydrodynamic Description of Granular Convection
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
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, , is one. However, if we relax this
condition slightly such that , 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
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
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
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Derivation of globally averaged lunar heat flow from the local heat flow values and the Thorium distribution at the surface: expected improvement by the LUNAR-A Mission
The relationship between the Th abundance and the heat flow data of the Apollo sites and the LUANR-A sites, where the Th concentrations are in the wide range from 1 ppm to 6 ppm, will allow for a more precise estimation of the averaged heat flow value
Collision of One-Dimensional Nonlinear Chains
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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