5,400 research outputs found

### Fermion Mass Generation in the D-dimensional Thirring Model as a Gauge Theory

Based on the Schwinger-Dyson (SD) equation, the fermion mass generation is
further studied in the D(2<D<4)-dimensional Thirring model as a gauge theory
previously proposed. By using a certain approximation to the kernel, we
analytically obtained explicit form of the dynamical mass of fermion and the
critical line in (N,1/g) space, where N is the number of fermions and g is the
dimensionless vector-type four-fermion coupling constant. This analytical
result is confirmed by the numerical solution for the SD equation with exact
form of the kernel in (2+1) dimensions.Comment: 21 pages, 2 Postscript figures, LaTe

### Identifications of the polar cap boundary and the auroral belt in the high altitude magnetosphere: A model for field aligned currents

Using the OGO-5 fluxgate magnetometer data, the polar cap boundary is identified in the high altitude magnetosphere by a sudden transition from a dipolar field to a more tail like configuration. The basic pattern of the magnetic field variations observed during the satellite's traversal of the auroral belt is presented. This pattern shows the existence of a field aligned current layer on the equator side of the polar cap boundary. Currents flow in the opposite directions in the two field aligned current layers. The current directions in these layers as observed by OGO-5 in the high-altitude magnetosphere are the same as those observed at low altitudes by the polar orbiting TRIAD satellite. The magnetic field in the region where the lower latitude field aligned current layer is situated is essentially meridional. Thus the equatorial current closure of this current system must be via the equatorial current sheet. The two field aligned current systems, one at the polar cap boundary and the other on the low latitude side of the auroral belt, are coupled through the Pedersen current in the ionosphere

### Magnetic fields and solar wind

Solar corpuscular radiation interaction with geomagnetic field - solar wind, interplanetary magnetic fields, magnetosphere boundary, and solar wind heating and sudden pressure change

### Field-aligned currents observed by the OGO 5 and Triad satellites

The existence of field-aligned currents in the polar cap boundary layer as a permanent feature of the magnetosphere is investigated. Magnetic field observations from Triad at 800 km altitude and from OGO 5 in the high-altitude magnetosphere are examined. Results indicate that in the morning half of the boundary layer, currents flow into the ionosphere, and that the current direction is reversed in the afternoon half of the layer. The Triad data further indicate that the net current is a maximum near 1500 MLT and that there may be a secondary maximum during early morning hours. According to the Isis 2 electron observations, the locations of these maximums of field-aligned net current roughly match those of two maximums in the isointensity contours for 150 ev electrons. It is proposed that the polar cap boundary current is driven by a current generator in the magnetotail, or ultimately in the solar wind. It is suggested that the large scale field-aligned currents in the polar cap boundary layer are associated with the dominance of protons on the morning side and of electrons on the afternoon side near the poleward edge of the precipitation zone along the auroral oval

### Joule heating and field-aligned currents: Preliminary results from DE-2

There are three main processes by which energy is transferred from the magnetosphere to the thermosphere: (1) charge exchange of the ring current particles; (2) precipitation of charged particles; and (3) joule dissipation by the magnetosphere-ionosphere current systems. The importance of this last process has been recognized and the rate of joule heating has been estimated by many workers. Observations of the electric (E) and magnetic (B) fields from Dynamics Explorer Satellite 2 are providing a new set of data on field-aligned currents. One of the remarkable features found in these observations is the high correlation between an orthogonal pair of the E and B field components. In recent years, observational data have accrued concerning the relationship between the interplanetary magnetic field and the size of the polar cap and also about the evolution of a substorm or a magnetic storm. It is suggested that these findings be incorporated in future model calculations

### Indices of Upper Atmospheric Disturbance Phenomena in Auroral Zone

The earlier orbits and ephemerides for the Soviet satellites were not sufficiently
accurate to be very useful in making observations in Alaska. Extrapolations
from our own observations gave better predictions. This merely pointed out the fact
that rough observations of meridian transits at high latitudes will give better values
of the inclination of the orbit than precision observations at low latitudes. Hence,
it was decided to observe visually the meridian transits estimating the altitude by
noting the position with respect to the stars or using crude alidade measurements.
The times of the earlier observations were observed on a watch or clock and the clock
correction obtained from WWV. Later the times were determined with the aid of stop
watches, taking time intervals from WWV signals.
This rather meager program of optical observations of the Soviet satellites was
undertaken to give supplementary data for use of the radio observations, and particularly
to assist in the prediction of position of the satellite so that the 61-foot
radar of Stanford Research Institute could be set accurately enough to observe it
(the beam width at the half-power points is about 3°).
This report contains primarily the visual observations made at the Geophysical
Institute by various members of the staff, and a series of observations by Olaf
Halverson at Nome, Alaska. In addition there is a short discussion of the geometry
of the trajectory, the illumination of a circumpolar satellite, and a note on the
evaluation of Brouwer's moment factors.IGY Project No. I.14
NSF Grant No. Y/l.14/1771. INTRODUCTION / C. T. Elvey and M. Sugiura -- KEY TO GRAPH
DISTURBANCE INDICES -- 2. HOURLY RADAR INDICES OF AURORAL ACTIVITY / R. S. Leonard -- 3. HOURLY INDICES OF GEOELECTRIC AND MAGNETIC ACTIVITY
/ V. P. Hessler --
4. HOURLY IONOSPHERIC ABSORPTION / H. Leinbach --
5. HOURLY PHOTOMETRIC INDICES OF AURORAL ACTIVITY / W. Murcray --
6. HOURLY SPECTROSCOPIC INDICES OF AURORAL ACTIVITY
/ G. J. Romick --
7. AURORAL INDICES USING THE ALL-SKY CAMERA FILM / G. H. StanleyYe

### Solar generated quasi-biennial geomagnetic variation

The existence of highly correlated quasi-biennial variations in the geomagnetic field and in solar activity is demonstrated. The analysis uses a numerical filter technique applied to monthly averages of the geomagnetic horizontal component and of the Zurich relative sunspot number. Striking correlations are found between the quasi-biennial geomagnetic variations determined from several magnetic observatories located at widely different longitudes, indicating a worldwide nature of the obtained variation. The correlation coefficient between the filtered Dst index and the filtered relative sunspot number is found to be -0.79 at confidence level greater than 99% with a time-lag of 4 months, with solar activity preceding the Dst variation. The correlation between the unfiltered data of Dst and of the sunspot number is also high with a similar time-lag. Such a timelag has not been discussed in the literature, and a further study is required to establish the mode of sun-earth relationship that gives this time delay

### 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 $\kappa$ 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 $\pi$ 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 $\pi$ 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

### Investigation of MAGSAT and TRIAD magnetometer data to provide corrective information on high-lattitude external fields

Disturbances in the MAGSAT magnetometer data set due to high latitude phenomena were evaluated. Much of the categorization of disturbances due to Birkeland currents, ionospheric Hall currents, fine structure and wave phenomena was done with the MAGSAT data catalog. A color graphics technique was developed for the display of disturbances from multiple orbits, from which one can infer a 'global-image' of the current systems of the auroral zone. The MAGSAT 4/81 magnetic field model appears to represent the Earth's main field at high latitudes very well for the epoch 1980. MAGSAT's low altitude allows analysis of disturbances in the magnetometer data due to ionospheric electrojet currents. These current distributions were modeled properly for single events as a precursor to the inference of the Birkeland current system. MAGSAT's orbit was approximately shared with that of the Navy/APL TRIAD satellite. This allowed space-time studies of the magnetic disturbance signatures to be performed, the result being an approximately 75% agreement in, as well as high frequency of, signatures due to Birkeland currents. Thus the field-aligned currents are a steady-state participant in the Earth's magnetospheric current system

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