6,855 research outputs found
Analytic Solutions to the RG Equations of the Neutrino Physical Parameters
In the case of two generation neutrinos, the energy-scale dependence of the
lepton-flavor mixing matrix with Majorana phase can be governed by only one
parameter r, which is the ratio between the diagonal elements of neutrino mass
matrix. By using this parameter r, we derive the analytic solutions to the
renormalization group equations of the physical parameters, which are the
mixing angle, Majorana phase, and the ratio of the mass-squared difference to
the mass squared of the heaviest neutrino. The energy-scale dependence of the
Majorana phase is clarified by using these analytic solutions. The instability
of the Majorana phase causes in the same parameter region in which the mixing
angle is unstable against quantum corrections.Comment: LaTeX2e, 9 pages, 6 figure
The effects of Majorana phases in three-generation neutrinos
Neutrino-oscillation solutions for the atmospheric neutrino anomaly and the
solar neutrino deficit can determine the texture of the neutrino mass matrix
according to three types of neutrino mass hierarchies as Type A: ,
Type B: , and Type C: , where is the -th generation neutrino absolute mass. The
relative sign assignments of neutrino masses in each type of mass hierarchies
play the crucial roles for the stability against quantum corrections. Actually,
two physical Majorana phases in the lepton flavor mixing matrix connect among
the relative sign assignments of neutrino masses. Therefore, in this paper we
analyze the stability of mixing angles against quantum corrections according to
three types of neutrino mass hierarchies (Type A, B, C) and two Majorana
phases. Two phases play the crucial roles for the stability of the mixing
angles against the quantum corrections.Comment: LaTeX2e, 15 pages, 8 figure
Energy-Scale Dependence of the Lepton-Flavor-Mixing Matrix
We study an energy-scale dependence of the lepton-flavor-mixing matrix in the
minimal supersymmetric standard model with the effective dimension-five
operators which give the masses of neutrinos. We analyze the renormalization
group equations of kappa_{ij}s which are coefficients of these effective
operators under the approximation to neglect the corrections of O(\kappa^2). As
a consequence, we find that all phases in do not depend on the
energy-scale, and that only n_g-1 (n_g: generation number) real independent
parameters in the lepton-flavor-mixing matrix depend on the energy-scale.Comment: 6 pages, no figur
The effect of Majorana phase in degenerate neutrinos
There are physical Majorana phases in the lepton flavor mixing matrix when
neutrinos are Majorana fermions. In the case of two degenerate neutrinos, the
physical Majorana phase plays the crucial role for the stability of the maximal
flavor mixing between the second and the third generations against quantum
corrections. The physical Majorana phase of guarantees the maximal mixing
to be stable against quantum corrections, while the Majorana phase of zero lets
the maximal mixing be spoiled by quantum corrections when neutrino masses are
of O(eV). The continuous change of the Majorana phase from to 0 makes the
maximal mixing be spoiled by quantum corrections with O(eV) degenerate neutrino
masses. On the other hand, when there is the large mass hierarchy between
neutrinos, the maximal flavor mixing is not spoiled by quantum corrections
independently of the Majorana phase.Comment: 7 pages, 1 figures, LaTe
Are lepton flavor mixings in the democratic mass matrix stable against quantum corrections?
We investigate whether the lepton flavor mixing angles in the so-called
democratic type of mass matrix are stable against quantum corrections or not in
the minimal supersymmetric standard model with dimension five operator which
induces neutrino mass matrix. By taking simple breaking patterns of or flavor symmetries and the scale where
democratic textures are induced as GeV, we find that the stability
of the lepton flavor mixing angles in the democratic type of mass matrix
against quantum corrections depends on the solar neutrino solutions. The
maximal flavor mixing of the vacuum oscillation solution is spoiled by the
quantum corrections in the experimental allowed region of . The
large angle MSW solution is spoiled by the quantum corrections in the region of
. The condition of is needed in order to
obtain the suitable mass squared difference of the small angle MSW solution.
These strong constraints must be regarded for the model building of the
democratic type of mass matrixComment: 12pages,LaTe
Goodness-of-Fit Tests for Symmetric Stable Distributions -- Empirical Characteristic Function Approach
We consider goodness-of-fit tests of symmetric stable distributions based on
weighted integrals of the squared distance between the empirical characteristic
function of the standardized data and the characteristic function of the
standard symmetric stable distribution with the characteristic exponent
estimated from the data. We treat as an unknown parameter,
but for theoretical simplicity we also consider the case that is
fixed. For estimation of parameters and the standardization of data we use
maximum likelihood estimator (MLE) and an equivariant integrated squared error
estimator (EISE) which minimizes the weighted integral. We derive the
asymptotic covariance function of the characteristic function process with
parameters estimated by MLE and EISE. For the case of MLE, the eigenvalues of
the covariance function are numerically evaluated and asymptotic distribution
of the test statistic is obtained using complex integration. Simulation studies
show that the asymptotic distribution of the test statistics is very accurate.
We also present a formula of the asymptotic covariance function of the
characteristic function process with parameters estimated by an efficient
estimator for general distributions
Holographic Screening Length in a Hot Plasma of Two Sphere
We study the screening length of a quark-antiquark pair moving in a hot
plasma living in two sphere manifold using AdS/CFT correspondence where
the background metric is four dimensional Schwarzschild-AdS black hole. The
geodesic solution of the string ends at the boundary is given by a stationary
motion in the equatorial plane as such the separation length of
quark-antiquark pair is parallel to the angular velocity . The
screening length and the bound energy are computed numerically using
Mathematica. We find that the plots are bounded from below by some functions
related to the momentum transfer of the drag force configuration. We
compare the result by computing the screening length in the quark-antiquark
reference frame where the gravity dual are "Boost-AdS" and Kerr-AdS black
holes. Finding relations of the parameters of both black holes, we argue that
the relation between mass parameters of the Schwarzschild-AdS black
hole and of the Kerr-AdS black hole in high temperature is given by
, where is the angular momentum
parameter.Comment: Major revision: title changed, adding authors, 13 pages, 8 figures,
etc. Accepted for publication in European Physical Journal
Si/Ge hole-tunneling double-barrier resonant tunneling diodes formed on sputtered flat Ge layers
We have demonstrated Si/Ge hole-tunneling double-barrier resonant tunneling diodes (RTDs) formed on flat Ge layers with a relaxation rate of 89% by our proposed method; in this method, the flat Ge layers can be directly formed on highly B-doped Si(001) substrates using our proposed sputter epitaxy method. The RTDs exhibit clear negative differential resistance effects in the static current–voltage (I–V) curves at room temperature. The quantized energy level estimation suggests that resonance peaks that appeared in the I–V curves are attributed to hole tunneling through the first heavy- and light-hole energy levels
Spectroscopic Observation on the Combustion Characteristics of Japanese Traditional Oil Lamp
In this research, spectroscopic measurement has been made to investigate the combustion characteristics of a Japanese traditional oil lamp, called toumyou, that has been used since ancient periods until present. Combustion characteristics, i.e. flame stability and temperature, were analyzed by using a temperature video camera. Spectral emission intensity of hydroxyl (OH) radical (band head of 310 nm) was measured by using a UV-visible spectrometer and visualized by a CCD camera while the brightness was measured using a lux meter. The experimental result showed that the flames of vegetable oils burned were stable and temperatures ranged over about 1000-2500ºC. In addition, the emission intensity of OH radical was successfully detected by the UV-visible spectrometry and visualized by the CCD Camera. The emission intensities of OH radical from flames of coconut oil and palm oil were higher than those of other tested vegetable oils. From measurement using a lux meter, it was obtained that coconut oil gives the brightest flame
Void-induced cross slip of screw dislocations in fcc copper
Pinning interaction between a screw dislocation and a void in fcc copper is
investigated by means of molecular dynamics simulation. A screw dislocation
bows out to undergo depinning on the original glide plane at low temperatures,
where the behavior of the depinning stress is consistent with that obtained by
a continuum model. If the temperature is higher than 300 K, the motion of a
screw dislocation is no longer restricted to a single glide plane due to cross
slip on the void surface. Several depinning mechanisms that involve multiple
glide planes are found. In particular, a depinning mechanism that produces an
intrinsic prismatic loop is found. We show that these complex depinning
mechanisms significantly increase the depinning stress
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