Auroral-Zone Geophysical Events and their Relationship to theMagnetosphere

Studies were made of inter-relations among VLF-ELF-ULF radio noises, ionospheric absorption, geomagnetic variations and aurora at the South Pole, Byrd and Eights Stations, Antarctica. Semi-diurnal peaks in the above geophysical parameters were found : these peaks occurred within a few hours before magnetic noon and others a few hours before magnetic midnight. A geophysical event which takes place in the day sector is called a D (day) event and night sector an N (night) event. The N event is similar to AKASOFU\u27s substorm. One N event consists of three phases called N-1,N-2 and N-3. Early in the evening the N-1 is the major part of the N event. In mid-evening, three phases co-exist. The N-3 is the dominant feature of the late evening N event. Observations made by the Injun III satellite showed that VLF hiss (main feature of the N-1) was observed at the boundary and beyond the region of trapped electrons in the dark sector. VLF chorus (main feature of N-3) was observed in the closed lines of force. From the above observations, we suggest that the physical characteristics of auroral zone are asymmetric with respect to the day-night major axis. VLF hiss and band-type aurora are the main features of the evening side (N-1). VLF chorus, ionospheric absorption, ULF and patchy and surface-like aurora are characteristics of a post-midnight region (N-3). The break-up (N-2) is the transition between N-1 and N-3

Cosmological Family Asymmetry and CP violation

We discuss how the cosmological baryon asymmetry can be achieved by the lepton family asymmetries of heavy Majorana neutrino decays and they are related to CP violation in neutrino oscillation, in the minimal seesaw model with two heavy Majorana neutrinos. We derive the most general formula for CP violation in neutrino oscillation in terms of the heavy Majorana masses and Yukawa mass term. It is shown that the formula is very useful to classify several models in which $e-$, $\mu-$ and $\tau-$leptogenesis can be separately realized and to see how they are connected with low energy CP violaton. To make the models predictive, we take texture with two zeros in the Dirac neutrino Yukawa matrix. In particular, we find some interesting cases in which CP violation in neutrino oscillation can happen while lepton family asymmetries do not exist at all. On the contrary, we can find $e-$, $\mu-$ and $\tau-$leptogenesis scenarios in which the cosmological CP violation and low energy CP violation measurable via neutrino oscillations are very closely related to each other. By determining the allowed ranges of the parameters in the models, we predict the sizes of CP violation in neutrino oscillation and $|V_{e3}^{MNS}|$. Finally, the leptonic unitarity triangles are reconstructed.Comment: 22 pages, 9 figures A figure caption correcte

A forward speed effects study on jet noise from several suppressor nozzles in the NASA/Ames 40- by 80-foot wind tunnel

A test program was conducted in a 40 by 80 foot wind tunnel to evaluate the effect of relative velocity on the jet noise signature of a conical ejector, auxiliary inlet ejector, 32 spokes and 104 tube nozzle with and without an acoustically treated shroud. The freestream velocities in the wind tunnel were varied from 0 to 103.6 m/sec (300 ft/sec) for exhaust jet velocities of 259.1 m/sec (850 ft/sec) to 609.6 m/sec (2000 ft/sec). Reverberation corrections for the wind tunnel were developed and the procedure is explained. In conjunction with wind tunnel testing the nozzles were also evaluated on an outdoor test stand. The wind tunnel microphone arrays were duplicated during the outdoor testing. The data were then extrapolated for comparisons with data measured using a microphone array placed on a 30.5 meter (100 ft) arc. Using these data as a basis, farfield to nearfield arguments are presented with regards to the data measured in the wind tunnel. Finally, comparisons are presented between predictions made using existing methods and the measured data

Threshold corrections to the radiative breaking of electroweak symmetry and neutralino dark matter in supersymmetric seesaw model

We study the radiative electroweak symmetry breaking and the relic abundance of neutralino dark matter in the supersymmetric type I seesaw model. In this model, there exist threshold corrections to Higgs bilinear terms coming from heavy singlet sneutrino loops, which make the soft supersymmetry breaking (SSB) mass for up-type Higgs shift at the seesaw scale and thus a minimization condition for the Higgs potential is affected. We show that the required fine-tuning between the Higgsino mass parameter mu and the SSB mass for up-type Higgs may be reduced at the electroweak scale, due to the threshold corrections. We also present how the parameter mu depends on the SSB B-parameter for heavy singlet sneutrinos. Since the property of neutralino dark matter is quite sensitive to the size of mu, we discuss how the relic abundance of neutralino dark matter is affected by the SSB B-parameter. Taking the SSB B-parameter of order of a few hundreds TeV, the required relic abundance of neutralino dark matter can be correctly achieved. In this case, dark matter is a mixture of bino and Higgsino, under the condition that gaugino masses are universal at the grand unification scale.Comment: 27 pages, 3 figures; references added, discussion about RGEs added, the version published on PR

Leptogenesis and Low energy CP violation, a link

How is CP violation of low energy related to CP violation required from baryon number asymmetry ? We give an example which shows a direct link between CP violation of neutrino oscillation and baryogenesis through leptogenesis.Comment: 3 pages and 2 figures, Talk presented at 4th Nufac02, July 1-6, 200

CP violation in neutrino oscillation and leptogenesis

We study the correlation between CP violation in neutrino oscillations and leptogenesis in the framework with two heavy Majorana neutrinos and three light neutrinos. Among three unremovable CP phases, a heavy Majorana phase contributes to leptogenesis. We show how the heavy Majorana phase contributes to Jarlskog determinant $J$ as well as neutrinoless double $\beta$ decay by identifying a low energy CP violating phase which signals the CP violating phase for leptogenesis. For some specific cases of the Dirac mass term of neutrinos, a direct relation between lepton number asymmetry and $J$ is obtained. For the most general case of the framework, we study the effect on $J$ coming from the phases which are not related to leptogenesis, and also show how the correlation can be lost in the presence of those phases.Comment: 4 pages and 3 figure

Effects of Alloying Elements and Cold Work on the Redistribution of Hydrogen in Zirconium under a Temperature Gradient

Effects of alloying elements (beryllium, hafnium, niobium, tin and yttrium) and of cold-swaging on the redistribution of hydrogen in zirconium with various initial hydrogen concentrations have been examined after anneals under given temperature differences. For low hydrogen concentration, the alloying elements did not greatly affect the value of the heat of transport, except for the beta-martensite Zr/1 wt% Nb alloy which showed a low value. Cold-swaging enhanced the migration of hydrogen toward the cold end. The heat of transport of the worked specimens could not be calculated accurately. For high hydrogen concentration, the α/(α+δ) interface moved toward the cold end. As the initial concentrations were different from alloy to alloy, a normalization process was employed. The resulting comparison showed that niobium accelerated the movement of the interface. This was attributed to the fine grain size of the alloy. The movement of the interface was also enhanced by cold-swaging which probably produced many defects and elongated grain boundaries along the temperature gradient, thereby accelerating diffusion of hydrogen toward the cold end