134,001 research outputs found
Thermal fluctuations and anomalous elasticity of homogeneous nematic elastomers
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
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
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
lepton flavor mixing matrix. Its mixing angles and
can be related to the mass ratios and in a
specific texture of lepton mass matrices with vanishing (1,1) elements:
and . The
latter relation, together with solar and atmospheric neutrino oscillation data,
predicts 0.0030 eV 0.0073 eV, 0.009 eV 0.012 eV and 0.042 eV 0.058 eV. The smallest
neutrino mixing angle is found to be , which is experimentally accessible in the near future.Comment: RevTex 10 pages, 2 figure
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