100,909 research outputs found
New Lepton Family Symmetry and Neutrino Tribimaximal Mixing
The newly proposed finite symmetry Sigma(81) is applied to the problem of
neutrino tribimaximal mixing. The result is more satisfactory than those of
previous models based on A_4 in that the use of auxiliary symmetries (or
mechanisms) may be avoided. Deviations from the tribimaximal pattern are
expected, but because of its basic structure, only tan^2 (theta_12) may differ
significantly from 0.5 (say 0.45) with sin^2 (2 theta_23) remaining very close
to one, and theta_13 very nearly zero.Comment: 8 pages, no figur
Suitability of A_4 as a Family Symmetry in Grand Unification
In the recent successful applications of the non-Abelian discrete symmetry
A_4 to the tribimaximal mixing of neutrinos, lepton doublets and singlets do
not transform in the same way. It appears thus to be unsuitable as a family
symmetry in grand unification. A simple resolution of this dilemma is proposed.Comment: 6 pages, no figur
Lepton flavor violating Higgs decays and unparticle physics
We predict the branching ratios of the lepton flavor violating Higgs decays
H^0->e^{\pm} \mu^{\pm}, H^0-> e^{\pm} \tau^{\pm} and H^0->\mu^{\pm} \tau^{\pm}
in the case that the lepton flavor violation is carried by the scalar
unparticle mediation. We observe that their branching ratios are strongly
sensitive to the unparticle scaling dimension and they can reach to the values
of the order of , for the heavy lepton flavor case and for the small
values of the scaling dimension.Comment: 12 pages, 7 Figures, 1 Table
Investigation of charge sharing among electrode strips for a CdZnTe detector
We have investigated charge sharing among the anode strips of a CdZnTe (CZT)
detector using a 30 micrometer collimated gamma-ray beam. We compared the
laboratory measurements with the predictions from our modeling of the charge
transport within the detector. The results indicate that charge sharing is a
function of the interaction depth and the energy of the incoming photon. Also,
depending on depth, a fraction of the electrons might drift to the inter-anode
region causing incomplete charge collection. Here, we show that photoelectron
range and diffusion of the charge cloud are the principal causes of charge
sharing and obtain limits on the size of the electron cloud as a function of
position in the detector.Comment: 16 pages 10 figures. Accepted for publication in Nuclear Instruments
and Methods -
Statistics of polymer adsorption under shear flow
Using non-equilibrium Brownian dynamics computer simulations, we have
investigated the steady state statistics of a polymer chain under three
different shear environments: i) linear shear flow in the bulk (no walls), ii)
shear vorticity normal to the adsorbing wall, iii) shear gradient normal to the
adsorbing wall. The statistical distribution of the chain end-to-end distance
and its orientational angles are calculated within our monomer-resolved
computer simulations. Over a wide range of shear rates, this distribution can
be mapped onto a simple theoretical finite-extensible-nonlinear-elastic
dumbbell model with fitted anisotropic effective spring constants. The tails of
the angular distribution functions are consistent with scaling predictions
borrowed from the bulk dumbbell model. Finally, the frequency of the
characteristic periodic tumbling motion has been investigated by simulation as
well and was found to be sublinear with the shear rate for the three set-ups,
which extends earlier results done in experiments and simulations for free and
tethered polymer molecules without adsorption.Comment: 10 figure
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