15,510 research outputs found
Oscillation parameters present: Session summary
© Copyright owned by the author(s) under the terms of the Creative Commons. Session I of the Neutrino Oscillation Workshop 2018 Conference, “Neutrino Oscillations: Present”, is summarised. Results were presented by the currently-running long-baseline oscillation experiments T2K and NOvA, as well as from the accelerator experiments OPERA and MiniBooNE. Status reports and results from experiments using short-baseline accelerator neutrinos (ICARUS and MicroBooNE), atmospheric neutrinos (Super-K, IceCube and ANTARES), and those from reactors (Daya Bay and Double Chooz), and from the Sun and the Earth (Borexino) were also presented. Our current knowledge of neutrino oscillation parameters depends significantly on the experimental inputs that inform us of details of the production and interactions of neutrinos, which were presented by the NA61/SHINE hadron production experiment and cross section measurements from T2K and MINERvA, as well as a review of the status of our understanding of neutrino production at nuclear reactors. The session also included theoretical reviews of the current status of neutrino oscillations, and phenomenological studies on neutrino tomography and experimental studies to support nuclear matrix element calculations (NUMEN)
Charge dynamics in thermally and doping induced insulator-metal transitions of (Ti1-xVx)2O3
Charge dynamics of (Ti1-xVx)2O3 with x=0-0.06 has been investigated by
measurements of charge transport and optical conductivity spectra in a wide
temperature range of 2-600K with the focus on the thermally and doping induced
insulator-metal transitions (IMTs). The optical conductivity peaks for the
interband transitions in the 3d t2g manifold are observed in the both
insulating and metallic states, while their large variation (by ~0.4 eV) with
change of temperature and doping level scales with that of the Ti-Ti dimer bond
length, indicating the weakened singlet bond in the course of IMTs. The
thermally and V-doping induced IMTs are driven with the increase in carrier
density by band-crossing and hole-doping, respectively, in contrast to the
canonical IMT of correlated oxides accompanied by the whole collapse of the
Mott gap.Comment: 4 pages, 4 figure
Synchronization and Collective Dynamics in a Carpet of Microfluidic Rotors
We study synchronization of an array of rotors on a substrate that are
coupled by hydrodynamic interaction. The rotors that are modeled by an
effective rigid body, are driven by an internal torque and exerts an active
force on the surrounding fluid. The long-ranged nature of the hydrodynamic
interaction between the rotors causes a rich pattern of dynamical behaviors
including phase ordering and turbulent spiral waves. The model provides a novel
example of coupled oscillators with long-range interaction. Our results suggest
strategies for designing controllable microfluidic mixers using the emergent
behavior of hydrodynamically coupled active components.Comment: 4 pages, 3 figure
Many-Body Theory of Synchronization by Long-Range Interactions
Synchronization of coupled oscillators on a -dimensional lattice with the
power-law coupling and randomly distributed intrinsic
frequency is analyzed. A systematic perturbation theory is developed to
calculate the order parameter profile and correlation functions in powers of
. For , the system exhibits a sharp
synchronization transition as described by the conventional mean-field theory.
For , the transition is smeared by the quenched disorder, and the
macroscopic order parameter \Av\psi decays slowly with as |\Av\psi|
\propto g_0^2.Comment: 4 pages, 2 figure
Coronal heating by stochastic magnetic pumping
Recent observational data cast serious doubt on the widely held view that the Sun's corona is heated by traveling waves (acoustic or magnetohydrodynamic). It is proposed that the energy responsible for heating the corona is derived from the free energy of the coronal magnetic field derived from motion of the 'feet' of magnetic field lines in the photosphere. Stochastic motion of the feet of magnetic field lines leads, on the average, to a linear increase of magnetic free energy with time. This rate of energy input is calculated for a simple model of a single thin flux tube. The model appears to agree well with observational data if the magnetic flux originates in small regions of high magnetic field strength. On combining this energy input with estimates of energy loss by radiation and of energy redistribution by thermal conduction, we obtain scaling laws for density and temperature in terms of length and coronal magnetic field strength
MHD Waves and Coronal Seismology: an overview of recent results
Recent observations have revealed that MHD waves and oscillations are
ubiquitous in the solar atmosphere, with a wide range of periods. We give a
brief review of some aspects of MHD waves and coronal seismology which have
recently been the focus of intense debate or are newly emerging. In particular,
we focus on four topics: (i) the current controversy surrounding propagating
intensity perturbations along coronal loops, (ii) the interpretation of
propagating transverse loop oscillations, (iii) the ongoing search for coronal
(torsional) Alfven waves and (iv) the rapidly developing topic of
quasi-periodic pulsations (QPP) in solar flares
Distribution of Faraday Rotation Measure in Jets from Active Galactic Nuclei II. Prediction from our Sweeping Magnetic Twist Model for the Wiggled Parts of AGN Jets and Tails
Distributions of Faraday rotation measure (FRM) and the projected magnetic
field derived by a 3-dimensional simulation of MHD jets are investigated based
on our "sweeping magnetic twist model". FRM and Stokes parameters were
calculated to be compared with radio observations of large scale wiggled AGN
jets on kpc scales. We propose that the FRM distribution can be used to discuss
the 3-dimensional structure of magnetic field around jets and the validity of
existing theoretical models, together with the projected magnetic field derived
from Stokes parameters. In the previous paper, we investigated the basic
straight part of AGN jets by using the result of a 2-dimensional axisymmetric
simulation. The derived FRM distribution has a general tendency to have a
gradient across the jet axis, which is due to the toroidal component of the
magnetic field generated by the rotation of the accretion disk. In this paper,
we consider the wiggled structure of the AGN jets by using the result of a
3-dimensional simulation. Our numerical results show that the distributions of
FRM and the projected magnetic field have a clear correlation with the large
scale structure of the jet itself, namely, 3-dimensional helix. Distributions,
seeing the jet from a certain direction, show a good matching with those in a
part of 3C449 jet. This suggests that the jet has a helical structure and that
the magnetic field (especially the toroidal component) plays an important role
in the dynamics of the wiggle formation because it is due to a current-driven
helical kink instability in our model.Comment: Accepted for publication in Ap
Recent Advances in Percutaneous Cardioscopy
Percutaneous cardioscopy, using high-resolution fiberoptic imaging, enables direct visualization of the cardiac interior, thereby enabling macroscopic pathological diagnosis. Percutaneous cardioscopy has demonstrated that the endocardial surface exhibits various colors characteristic of different heart diseases. This imaging modality can now be used for evaluation of the severity of myocardial ischemia, and staging of myocarditis. Myocardial blood flow recovery induced by vasodilating agents or percutaneous coronary interventions can be clearly visualized. Morphological and functional changes in the cardiac valves can also be evaluated. Cardioscope-guided endomyocardial biopsy enables pin-point biopsy of the diseased myocardium. Recently, dye-image cardioscopy and fluorescence cardioscopy were developed for evaluation of the subendocardial microcirculation. Cardioscope-guided intracardiac therapies such as myotomy, myectomy, valvulotomy, and transendocardial angiogenic and myogenic therapy have been trialed using animal models in anticipation of future clinical applications. Percutaneous cardioscopy has the potential to contribute to our understanding of heart disease, and to assist in guidance for intracardiac therapies
NMR and NQR study of pressure-induced superconductivity and the origin of critical-temperature enhancement in the spin-ladder cuprate SrCaCuO
Pressure-induced superconductivity was studied for a spin-ladder cuprate
SrCaCuO using nuclear magnetic resonance (NMR) under
pressures up to the optimal pressure 3.8 GPa. Pressure application leads to a
transitional change from a spin-gapped state to a Fermi-liquid state at
temperatures higher than . The relaxation rate shows
activated-type behavior at an onset pressure, whereas Korringa-like behavior
becomes predominant at the optimal pressure, suggesting that an increase in the
density of states (DOS) at the Fermi energy leads to enhancement of .
Nuclear quadrupole resonance (NQR) spectra suggest that pressure application
causes transfer of holes from the chain to the ladder sites. The transfer of
holes increases DOS below the optimal pressure. A dome-shaped versus
pressure curve arises from naive balance between the transfer of holes and
broadening of the band width
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