6,866 research outputs found
Mass Matrices in E6 Unification
We study a supersymmetric E6 grand unified model in which the SU(5) 5^*
components are twisted in the third generation 27. Supplementing the adjoint
Higgs field to a model analyzed previously, we calculate the mass matrices for
the up and down quarks and charged leptons. Although the number of free
parameters is less than that of observables, an overall fitting to the observed
masses and mixing angles is shown to be possible. Most notably, we find two
novel, parameter-independent relations between the lepton 2-3 mixing angle and
the quark masses and CKM mixing angles that are in good agreement with the
large lepton mixing recently observed.Comment: 33 pages, 5 figures, typos correcte
Cluster synchronization in an ensemble of neurons interacting through chemical synapses
In networks of periodically firing spiking neurons that are interconnected
with chemical synapses, we analyze cluster state, where an ensemble of neurons
are subdivided into a few clusters, in each of which neurons exhibit perfect
synchronization. To clarify stability of cluster state, we decompose linear
stability of the solution into two types of stabilities: stability of mean
state and stabilities of clusters. Computing Floquet matrices for these
stabilities, we clarify the total stability of cluster state for any types of
neurons and any strength of interactions even if the size of networks is
infinitely large. First, we apply this stability analysis to investigating
synchronization in the large ensemble of integrate-and-fire (IF) neurons. In
one-cluster state we find the change of stability of a cluster, which
elucidates that in-phase synchronization of IF neurons occurs with only
inhibitory synapses. Then, we investigate entrainment of two clusters of IF
neurons with different excitability. IF neurons with fast decaying synapses
show the low entrainment capability, which is explained by a pitchfork
bifurcation appearing in two-cluster state with change of synapse decay time
constant. Second, we analyze one-cluster state of Hodgkin-Huxley (HH) neurons
and discuss the difference in synchronization properties between IF neurons and
HH neurons.Comment: Notation for Jacobi matrix is changed. Accepted for publication in
Phys. Rev.
Phenomenology of Neutrino Mass Matrix
The search for possible mixing patterns of charged leptons and neutrinos is
important to get clues of the origin of nearly maximal mixings, since there are
some preferred bases of the lepton mass matrices given by underlying theories.
We systematically examine the mixing patterns which could lead to large lepton
mixing angles. We find out 37 mixing patterns are consistent with experimental
data if taking into account phase factors in the mixing matrices. Only 6
patterns of them can explain the observed data without any tuning of
parameters, while the others need particular choices for phase values.Comment: revised reference
Monolithic superconducting emitter of tunable circularly polarized terahertz radiation
We propose an approach to control the polarization of terahertz (THz)
radiation from intrinsic Josephson-junction stacks in single crystalline
high-temperature superconductor . By monolithically
controlling the surface current distributions in the truncated square mesa
structure, we can modulate the polarization of the emitted THz wave as a result
of two orthogonal fundamental modes excited inside the mesa. Highly polarized
circular terahertz waves with a degree of circular polarization of more than
99% can be generated using an electrically controlled method. The emitted
radiation has a high intensity and a low axial ratio (AR<1 dB). The intuitive
results obtained from the numerical simulation based on the conventional
antenna theory are consistent with the observed emission characteristics.Comment: Submitted to PRApplie
Complete mitochondrial DNA sequence of the parasitic honey bee mite Varroa destructor (Mesostigmata : Varroidae)
Varroa destructor is a parasite mite of the eastern honey bee Apis cerana, which is native to Asia. The European honey bee Apis mellifera was imported to Asia from Europe and the USA for apiculture in the 19th century. In a short period of time, V. destructor parasitized the artificially introduced honey bees. Varroa destructor was estimated to have spread around the world with A. mellifera when it was exported from Asia to locations worldwide about 50 years ago. The mitochondrial DNA of the parasitic honey bee mite V. destructor was analyzed using next-generation sequencing. The complete mitochondrial genome of V. destructor was identified as a 16,476-bp circular molecule containing 13 protein-coding genes (PCGs), 22 tRNA genes, two rRNA genes, and one AT-rich control region. The heavy strand was predicted to have nine PCGs and 13 tRNA genes, whereas the light strand was predicted to contain four PCGs, nine tRNA genes, and two rRNA genes. All PCGs began with ATA as the start codon, except COIII and CytB, which had ATG as the start codon. Stop codons were of two types: TAA for eight genes and TAG for five genes. Molecular phylogenetic analysis revealed that V. destructor from Japan was genetically distant from that of France. A high base substitution rate of 2.82% was also confirmed between the complete mitochondrial DNA sequences of V. destructor from Japan and the USA, suggesting that one Varroa mite strain found in the USA is not from Japan
Gap Condition and Self-Dualized Super Yang-Mills Theory for ADE Gauge Group on K3
We try to determine the partition function of super Yang-Mills
theoy for ADE gauge group on K3 by self-dualizing our previous ADE partition
function. The resulting partition function satisfies gap condition.Comment: 17 page
Polarization Enhancement of terahertz radiation generated by intrinsic Josephson junctions in a truncated edge square Bi_{2}Sr_{2}CaCu_{2}O_{8+{\delta}} mesa
In this study, we investigated the terahertz radiation from a truncated edge
square mesa structure made from a superconducting
Bi_{2}Sr_{2}CaCu_{2}O_{8+{\delta}} . Using a commercial software, the
polarization characteristics were determined, and introduced, while accounting
for the skin effect. The axial ratio was enhanced in the simulation by
performing a parametric study on the design.Comment: Proceedings of the 28th International Symposium on Superconductivity,
ISS 2015, November 16-18, 2015, Tokyo, Japa
Intermediate left-right gauge symmetry, unification of couplings and fermion masses in SUSY
If left-right gauge theory occurs as an intermediate symmetry in a GUT then,
apart from other advantages, it is possible to obtain the see-saw scale
necessary to understand small neutrino masses with Majorana coupling of order
unity. Barring threshold or non-renormalizable gravitational effects, or
assumed presence of additional light scalar particles of unprescribed origin,
all other attempts to achieve manifest one-loop gauge coupling unification in
SUSY SO(10) with left-right intermediate symmetry have not been successful so
far. Attributing this failure to lack of flavor symmetry in the GUT, we show
how the spontaneous symmetry breaking of leads to such
intermediate scale extending over a wide range, GeV
to GeV. All the charged fermion masses are fitted at the see-saw
scale, GeV which is obtained with
Majorana coupling . Using a constrained parametrization in which
CP-violation originates only from quark sector, besides other predictions made
in the neutrino sector, the reactor mixing angle is found to be which is in the range accessible to ongoing and
planned experiments. The leptonic Dirac phase turns out to be radians with Jarlskog invariant .Comment: Minor clarification and few references added to match the published
versio
Primary-Filling e/3 Quasiparticle Interferometer
We report experimental realization of a quasiparticle interferometer where
the entire system is in 1/3 primary fractional quantum Hall state. The
interferometer consists of chiral edge channels coupled by quantum-coherent
tunneling in two constrictions, thus enclosing an Aharonov-Bohm area. We
observe magnetic flux and charge periods h/e and e/3, equivalent to creation of
one quasielectron in the island. Quantum theory predicts a 3h/e flux period for
charge e/3, integer statistics particles. Accordingly, the observed periods
demonstrate the anyonic statistics of Laughlin quasiparticles
Linear stability analysis of retrieval state in associative memory neural networks of spiking neurons
We study associative memory neural networks of the Hodgkin-Huxley type of
spiking neurons in which multiple periodic spatio-temporal patterns of spike
timing are memorized as limit-cycle-type attractors. In encoding the
spatio-temporal patterns, we assume the spike-timing-dependent synaptic
plasticity with the asymmetric time window. Analysis for periodic solution of
retrieval state reveals that if the area of the negative part of the time
window is equivalent to the positive part, then crosstalk among encoded
patterns vanishes. Phase transition due to the loss of the stability of
periodic solution is observed when we assume fast alpha-function for direct
interaction among neurons. In order to evaluate the critical point of this
phase transition, we employ Floquet theory in which the stability problem of
the infinite number of spiking neurons interacting with alpha-function is
reduced into the eigenvalue problem with the finite size of matrix. Numerical
integration of the single-body dynamics yields the explicit value of the
matrix, which enables us to determine the critical point of the phase
transition with a high degree of precision.Comment: Accepted for publication in Phys. Rev.
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