181,860 research outputs found
Lorentz violation dispersion relation and its application
We derive a modified dispersion relation (MDR) in the Lorentz violation
extension of quantum electrodynamics (QED) sector in the standard model
extension (SME) framework. Based on the extended Dirac equation and
corresponding MDR, we observe the resemblance of the Lorentz violation coupling
with spin-gravity coupling. We also develop a neutrino oscillation mechanism
induced by the presence of nondiagonal terms of Lorentz violation couplings in
2-flavor space in a 2-spinor formalism by explicitly assuming neutrinos to be
Marjorana fermions. We also obtain a much stringent bound ()
on one of the Lorentz violation parameters by applying MDR to the ultrahigh
energy cosmic ray (UHECR) problem.Comment: 22 Latex pages, final version in publicatio
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
Neutrino Mass from Triplet and Doublet Scalars at the TeV Scale
If the minimal standard model of particle interactions is extended to include
a scalar triplet with lepton number and a scalar doublet with ,
neutrino masses eV is possible,
where GeV is the electroweak symmetry breaking scale,
TeV is the typical mass of the new scalars, and GeV is a soft
lepton-number-violating parameter.Comment: 6 pages, no figur
Shifting with
Precision measurements at the resonance agree well with the standard
model. However, there is still a hint of a discrepancy, not so much in by
itself (which has received a great deal of attention in the past several years)
but in the forward-backward asymmetry together with . The two
are of course correlated. We explore the possibilty that these and other
effects are due to the mixing of and with one or more heavy quarks.Comment: 11 pages, 1 Figure, LaTex fil
Dynamic Transitions for Quasilinear Systems and Cahn-Hilliard equation with Onsager mobility
The main objectives of this article are two-fold. First, we study the effect
of the nonlinear Onsager mobility on the phase transition and on the
well-posedness of the Cahn-Hilliard equation modeling a binary system. It is
shown in particular that the dynamic transition is essentially independent of
the nonlinearity of the Onsager mobility. However, the nonlinearity of the
mobility does cause substantial technical difficulty for the well-posedness and
for carrying out the dynamic transition analysis. For this reason, as a second
objective, we introduce a systematic approach to deal with phase transition
problems modeled by quasilinear partial differential equation, following the
ideas of the dynamic transition theory developed recently by Ma and Wang
Exploration of Resonant Continuum and Giant Resonance in the Relativistic Approach
Single-particle resonant-states in the continuum are determined by solving
scattering states of the Dirac equation with proper asymptotic conditions in
the relativistic mean field theory (RMF). The regular and irregular solutions
of the Dirac equation at a large radius where the nuclear potentials vanish are
relativistic Coulomb wave functions, which are calculated numerically.
Energies, widths and wave functions of single-particle resonance states in the
continuum for ^{120}Sn are studied in the RMF with the parameter set of NL3.
The isoscalar giant octupole resonance of ^{120}Sn is investigated in a fully
consistent relativistic random phase approximation. Comparing the results with
including full continuum states and only those single-particle resonances we
find that the contributions from those resonant-states dominate in the nuclear
giant resonant processes.Comment: 16 pages, 2 figure
Realistic Gluino Axion Model Consistent with Supersymmetry Breaking at the TeV Scale
The recently proposed model of using the dynamical phase of the gluino to
solve the strong CP problem is shown to admit a specific realization in terms
of fundamental singlet superfields, such that the breaking of supersymmetry
occurs only at the TeV scale, despite the large axion scale of 10^{9} to
10^{12} GeV. Phenomenological implications are discussed.Comment: 12 pp, 2 fig
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